Add basic specs on Find.
Move existing Find implementation to 1.8 stdlib.
Import Find for 1.9 and 2.0.
Adapted heftig's encdir patch. Closes #2468.

We don't set @encdir so 'unless @encdir' is superfluous.
Merge pull request #2470 from razielgn/lib-find

Import Find from MRI for 1.9 and 2.0, with basic specs.
Run Travis on compiler branch while WIP. [ci skip].
Add specs on Marshal.load with encoding-less strings.
Marshal.load: deserialize encoding-less strings as ASCII-8BIT.
Merge pull request #2472 from razielgn/fix-marshal-string-encoding

Marshal.load: deserialize encoding-less strings as ASCII-8BIT.
Update array.rb

fixed comment for __permute__ method
Merge pull request #2473 from vredniy/patch-1

Update array.rb
Add specs for Module#remove_method
Fix Module#remove_method
Add specs for Module#undef_method
Add specs for a C-API rb_undef_method
Fix Module#undef_method