Adding 'lib' directory as placeholder

'lib' directory will act as a place holder for keeping the external
library. Since empty directory cannot be added to repo, a readme file is
created
Removed .pro.user file

It should not have been committed in the first place
Added project git ignore file

Added project git ignore file to ignore lib directory and .pro.user file
Fixed compilation and linker errors

1) Fixed compilation errors due to #endif without #if
2) Fixed linker errors due to not exporting JobManager
3) Fixed linker error due to exporting CommonTrackModel which is header
only
4) Remover reference non-existant coreutil/Settings.h from pri file