[13:56:24 INFO]: Client> [13:56:24] [Client thread/ERROR] [FML]: Caught exception from BuildCraft|Core
[13:56:24 INFO]: Client> java.lang.NoSuchMethodError: buildcraft.core.ItemBuildCraft.setCreativeTab(Lnet/minecraft/creativetab/CreativeTabs;)Lnet/minecraft/item/Item;
[13:56:24 INFO]: Client> at buildcraft.core.ItemBuildCraft.(ItemBuildCraft.java:30) ~[ItemBuildCraft.class:?]
[13:56:24 INFO]: Client> at buildcraft.core.ItemBuildCraft.(ItemBuildCraft.java:24) ~[ItemBuildCraft.class:?]
[13:56:24 INFO]: Client> at buildcraft.core.ItemWrench.(ItemWrench.java:31) ~[ItemWrench.class:?]
[13:56:24 INFO]: Client> at buildcraft.BuildCraftCore.loadConfiguration(BuildCraftCore.java:258) ~[BuildCraftCore.class:?]
[13:56:24 INFO]: Client> at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_05]
[13:56:24 INFO]: Client> at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_05]
[13:56:24 INFO]: Client> at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_05]
[13:56:24 INFO]: Client> at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.8.0_05]
[13:56:24 INFO]: Client> at cpw.mods.fml.common.FMLModContainer.handleModStateEvent(FMLModContainer.java:513) ~[forge-1.7.10-10.13.0.1180.jar:?]
[13:56:24 INFO]: Client> at sun.reflect.GeneratedMethodAccessor3.invoke(Unknown Source) ~[?:?]
[13:56:24 INFO]: Client> at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_05]
[13:56:24 INFO]: Client> at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.8.0_05]
[13:56:24 INFO]: Client> at com.google.common.eventbus.EventSubscriber.handleEvent(EventSubscriber.java:74) ~[guava-16.0.jar:?]
[13:56:24 INFO]: Client> at com.google.common.eventbus.SynchronizedEventSubscriber.handleEvent(SynchronizedEventSubscriber.java:47) ~[guava-16.0.jar:?]
[13:56:24 INFO]: Client> at com.google.common.eventbus.EventBus.dispatch(EventBus.java:322) ~[guava-16.0.jar:?]
[13:56:24 INFO]: Client> at com.google.common.eventbus.EventBus.dispatchQueuedEvents(EventBus.java:304) ~[guava-16.0.jar:?]
[13:56:24 INFO]: Client> at com.google.common.eventbus.EventBus.post(EventBus.java:275) ~[guava-16.0.jar:?]
[13:56:24 INFO]: Client> at cpw.mods.fml.common.LoadController.sendEventToModContainer(LoadController.java:208) ~[forge-1.7.10-10.13.0.1180.jar:?]
[13:56:24 INFO]: Client> at cpw.mods.fml.common.LoadController.propogateStateMessage(LoadController.java:187) ~[forge-1.7.10-10.13.0.1180.jar:?]
[13:56:24 INFO]: Client> at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_05]
[13:56:24 INFO]: Client> at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_05]
[13:56:24 INFO]: Client> at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_05]
[13:56:24 INFO]: Client> at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.8.0_05]
[13:56:24 INFO]: Client> at com.google.common.eventbus.EventSubscriber.handleEvent(EventSubscriber.java:74) ~[guava-16.0.jar:?]
[13:56:24 INFO]: Client> at com.google.common.eventbus.SynchronizedEventSubscriber.handleEvent(SynchronizedEventSubscriber.java:47) ~[guava-16.0.jar:?]
[13:56:24 INFO]: Client> at com.google.common.eventbus.EventBus.dispatch(EventBus.java:322) ~[guava-16.0.jar:?]
[13:56:24 INFO]: Client> at com.google.common.eventbus.EventBus.dispatchQueuedEvents(EventBus.java:304) ~[guava-16.0.jar:?]
[13:56:24 INFO]: Client> at com.google.common.eventbus.EventBus.post(EventBus.java:275) ~[guava-16.0.jar:?]
[13:56:24 INFO]: Client> at cpw.mods.fml.common.LoadController.distributeStateMessage(LoadController.java:118) [LoadController.class:?]
[13:56:24 INFO]: Client> at cpw.mods.fml.common.Loader.preinitializeMods(Loader.java:513) [Loader.class:?]
[13:56:24 INFO]: Client> at cpw.mods.fml.client.FMLClientHandler.beginMinecraftLoading(FMLClientHandler.java:239) [FMLClientHandler.class:?]
[13:56:24 INFO]: Client> at net.minecraft.client.Minecraft.func_71384_a(Minecraft.java:480) [bao.class:?]
[13:56:24 INFO]: Client> at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:867) [bao.class:?]
[13:56:24 INFO]: Client> at net.minecraft.client.main.Main.main(SourceFile:148) [Main.class:?]
[13:56:24 INFO]: Client> at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_05]
[13:56:24 INFO]: Client> at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_05]
[13:56:24 INFO]: Client> at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_05]
[13:56:24 INFO]: Client> at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.8.0_05]
[13:56:24 INFO]: Client> at net.minecraft.launchwrapper.Launch.launch(Launch.java:134) [launchwrapper-1.9.jar:?]
[13:56:24 INFO]: Client> at net.minecraft.launchwrapper.Launch.main(Launch.java:28) [launchwrapper-1.9.jar:?]

From the README:

Do not open an issue if you're not planning to fix it, instead open a thread on http://mod-buildcraft.com/forums/index.php?board=2.0
[...]
Always include the version you are having trouble with. Or if you're building from source, which source you're building. If you don't, we might assume that you are using latest-greatest and waste a bunch of time trying to reproduce a problem that might have fixed been already. Such things makes for very grumpy devs. Grumpy devs spend less time coding and more time doing stuff that makes them less grumpy.

Also, I don't suggest Java 1.8 (if I'm reading the version numbers right).

And learn how to build valid binaries from code. You tried to run dev (not obfuscated) build onto obfuscated minecraft. You need to run ./gradlew jar reobf for getting obfucated jar.