Updated Buildcraft Gears

-Ported 1.4.7 BC gear textures
Reversing merge due to checking in many commit conflict resolution files (for example solder.png~9e747f822d38b3b5a61ce597e26c55f6b109189e) which caused textures reverting to old versions and deleted textures.

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Let's try again to have the merge with Leenhaart take. :P (reverse-merged from commit 299bb6a4572d41b5ecb9ab6dd88912561906e25f)
Reverse merging Buildcraft, Forestry and Minefactory_Reloaded directories due to this branch checking in old textures and merge conflict files.

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Clear out BC, Forestry and MFR to allow merge with main from Leenhaart's pull request and resulting conflicts. (reverse-merged from commit d0a160ce085999ce8d66f82c87689a8602e1c0ad)
Cherry-picked commit Many Forestry fixes (and some Buildcraft/Plugins For Forestry fixes) (commit id 84f470df20be125789fac0820c88eee0917c0148)

Only the Forestry changes are commited, minus the conflict resolution files and texture reversions.
Cherry-picked commit Unstitched Power Converters (commit id 7594f614df577441947de1c0eb87bf99c727b6c5)

Moved out of MFR to its own directory.
Added Invar Armor item textures (Thermal Expansion).
Railcraft GUI update.

Updated broken and misaligned GUIs for loaders, carts and detectors.
Forestry update.

- Updated Forestry tree leaves for vanilla tree species to match JSTR leaves, including a fix for jungle "fast mode" leaves which were incorrect in the JSTR base textures.
- Fixed category numerals on the Beealyzer/Treealyzer GUI.