Don't catch ImportError unless it is related to the non-package import
Fix importerror catching in pypy
Add tests for importerror testcase
Fix sys.modules cleaning
Add test for Python 3.3 behaviour
Fix stupid error: s/version/version_info/
Merge pull request #56 from sjagoe/fix-overzealous-importerror-catch

Don't catch ImportError unless it is related to the non-package import