extract library properties from project properties
introduce projectProperties.libraries
introduce project properties helper, to handle external libraries
extract ExternalTreeEntry class
mark usage of externals
separate helper
load internal properties: use .model preferences
all tests use WorkspaceTest; workspace is reset every time
cleanup and reorganize tests
ext libs helper
external libs helper needs to know the project's base dir
start implementing ExternalLibrariesHelper.merge
remove app_meta.erl; use rebar.config instead
move ebinDir to library properties
small cleanups
remove unused code in erlide_open
extract erlide_libraries.erl
small api change for libraries helper
libraries tests
Merge branch 'library_properties' into pu