Merge some unmerged pull requests from 1.6.4 branch

This merges all my pull requests from the 1.6 branch that never made it into the 1.7 branch

Note: There are some other significant commits that never made it into the 1.7 branch; for example: https://github.com/SlimeKnights/TinkersConstruct/commit/34a4c8c80f969cafd696b41d963c2a041347d4cd which changed a lot about haste/mining speeds/etc (see [this reddit thread](http://www.reddit.com/r/feedthebeast/comments/24lsm4/psa_undocumented_changes_in_tinkers_construct/) for an explanation of the changes made in that commit).

It'd almost certainly be worth it (though it will take a lot of effort) to comb through this list: https://github.com/SlimeKnights/TinkersConstruct/compare/1.6.4 and make sure to cherry pick every relevant commit. 
However, I'm not sure if merging this will make it harder to merge other (older) commits from the 1.6 branches into 1.7.