updated expression templates
small fix
fix in VersionLocator
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