Updates. Gradle, NEI, Buildcraft.

Updated Gradle wrapper to 1.11 might have been pointless.

Decided to get rid of build.properties and just put the info directly
into build.gradle.

Added dependencies for CodeChickenLib, FMP, CCCore and NEI, all of which
are auto-downloaded.

Updated Gui stuff to the latest Lib and NEI, fixing Tool Tips if NEI is
installed and (I think) allowing NEI to place around Tabs when we add
them.

Updated Buildcraft API for the new 6.0 branch, removing the
RefineryRecipes class and instead using the new IMC system. Also updated
the IronEngineFuel and IToolWrench classes, although they only have
minor cosmetic changes.