Issue Description:

EnderIO power interface is making invalid assumption on CoFH Energy blocks

What happens:

When connecting with a tile entity implementing both IEnergyReceiver and IEnergyProvider, EnderIO only check for the latest and doesn't realize that the same tile entity can also receive energy.
As seen here: https://github.com/SleepyTrousers/EnderIO/blob/master/src/main/java/crazypants/enderio/power/PowerHandlerUtil.java#L21

What you expected to happen:

EnderIO should support tile entities with both direction of RF energy.

Steps to reproduce:

1. place a WarpDrive energy bank
2. fill the bank with energy by placing a EnderIO creative capacitor next to it
3. empty the bank with energy by placing an empty EnderIO capacitor next to it

Affected Versions (Do not use "latest"):

• EnderIO: EnderIO-1.7.10-2.3.0.424_beta-dev
• EnderCore: EnderCore-1.7.10-0.2.0.31_beta-dev
• Minecraft: 1.7.10
• Forge: 10.13.4.1490

Your most recent log file where the issue was present:

N/A

Umm - I don't know why you think the code is wrong - but it actually checks for IEnergyHandler first, and the EnergyHandlerPI class is both input and output.

PowerHandlerUtil assums you can't be both IEnergyReceiver and IEnergyProvider which is incorrect as reported in the API comments here: https://github.com/SleepyTrousers/EnderIO/blob/master/src/main/java/cofh/api/energy/IEnergyHandler.java#L15

I've got confused with another bug in my mod, there's indeed no missing in EnergyHanderPI. I've updated the original post accordingly.

but it actually checks for IEnergyHandler first

Didn't that get deprecated as separate interface and is now just a shorthand for receiver+provider?

yes, that's the object of this issue and the related pull request