Simplify WebappRepository.exists(), fixing it for empty directories.
Simplify WebappRepository.exists(), fixing it for empty directories.

ringo/ringojs,Transcordia/ringojs,ringo/ringojs,ashwinrayaprolu1984/ringojs,ringo/ringojs,oberhamsi/ringojs,Transcordia/ringojs,ashwinrayaprolu1984/ringojs,Transcordia/ringojs,Transcordia/ringojs,oberhamsi/ringojs,ringo/ringojs,ashwinrayaprolu1984/ringojs,ashwinrayaprolu1984/ringojs,oberhamsi/ringojs