improved GC behavior for 1.9.3-p392 railsexpress patches.
Merge pull request #1643 from skaes/ruby-193-p392-railsexpress-bugfixes

improved GC behavior for 1.9.3-p392 railsexpress patches.
prevent loading function when in posix mode, closes #1648
Merge branch 'master' of github.com:wayneeseguin/rvm