Issue description:

The Constructor and the Fluid Grid don't handle partial bucket amounts of fluid correctly.

What happens:

The Constructor places full blocks of fluid even if there's less than 1 Bucket of that fluid in the storage.

The Fluid grid returns empty buckets and voids fluids if there's not a full bucket in the storage.

What you expected to happen:

I'd expect both the Constructor and the Fluid Grid to not do anything under that condition.

Steps to reproduce:

1. Set up a RS system with fluid storage.
2. Set up an Importer on any tank with fluid in non-whole bucket quantities (e.g. 400 mB)
3. a) set up a Constructor to place that fluid in the world.
   b) Shift-click the fluid in the Fluid Grid while having an empty Bucket in the player inventory or the RS system.

Version (Make sure you are on the latest version before reporting):

• Minecraft: 1.10.2
• Forge: 12.8.2.2124
• Refined Storage: 1.2.4
• EnderStorage (and dependencies) - only to have the possibility of fluid amounts other than whole buckets.

Does this issue occur on a server? Yes (but with a lot more mods). Tested in Single player with only the above mods installed.