Fix regression spec on case-insensitive fs [skip ci]

When the file does not exist, it should raise LoadError.

Fixes https://github.com/jruby/jruby/issues/758
Update RubyGems to 2.0.7
Revert "Fix regression spec on case-insensitive fs [skip ci]"

This reverts commit db349bd7aac4d10b43bd3dd1f7873bcdd10e4ffa.
Remove JRUBY-5811 regression spec

Case-insensitive `LOADED_FEATURES` scanning is abandoned (65c07ea).

Fixes #758.
Merge branch 'master' into rubygems-2.0.7
Update tzdata to 2013d
Merge branch 'rubygems-2.0.7'
Use snapshot of joda-timezones artifact in transition to release.
Update to json 1.8.0.
Update joda-timezones to 2013d release.
Update to jruby-launcher 1.0.19.
cleanup obsolete files [skip CI]
added src release to jruby-dist [skip ci]
move requireTest.jar to test directory
obsolete [skip ci]
add the moved jar now
get the requireTest jar in test classpath
moved bouncy castle gem and use ruby-maven for building it
fixed url [skip ci]
gets copied from main lib/ruby/shared directory [skip ci]