Backporting a Ruby 1.9.3 fix for MissingSourceFile

[jescalante]

I backported a Ruby 1.9.3 fix in MissingSourceFile from Rails master.
In Ruby 1.9.3 a new error message was added when the LoadFile exception is thrown; this was fixed in Rails Master but not in 2-3-stable, rendering 2-3-stable unusable with Ruby 1.9.3

This is the specific line from master: https://github.com/rails/rails/blob/master/activesupport/lib/active_support/core_ext/load_error.rb#L6

[josevalim]

Thanks but Rails 2-3 is no longer maintained.

[elia]

@josevalim this probably can be merged after @dhh's comment on #3650

[grosser]

FYI: monkeypatch would be:
MissingSourceFile::REGEXPS << [/^cannot load such file -- (.+)$/i, 1]

[elia]

@spaghetticode will you include this in spaghetticode/rails2ext?

[spaghetticode]

@elia sure I will