Add gitignore
Handle classpath entries that point to non-existing filing system directories

Currently, the library throws an exception, which causes big issues
This seems to be quite a common occurance
Servers might add an 'override' folder to drop classes into for example
The patch is the minimal necessary to work around the problem
Fixes issue 148 at Sourceforge
Merge pull request #3 from jodastephen/non-existing-directory

Non existing directory