refactored the compression of the test direcotiries
ProjectManager now fires an event before inserting a project
added new test project
Merge remote-tracking branch 'origin/gsitter' into chartinger
fix phpspecs
Merge remote-tracking branch 'origin/gsitter' into chartinger
added missing project xml validation on project upload
added missing image validation at insert project
extracted file validators now registered via event
upload: missing fileChecksum test added
check checksum of uploaded file
added 501 error
check for undefined images
refactoring
check for invalid xml
check for invalid project file
Merge pull request #2 from Catrobat/Admin-Sonata

Shown in Meeting
Merge remote-tracking branch 'origin/master' into chartinger
added sonata compatibility to core
removed custom sonata bundle
updated readme