Add new element containing paths to check into the project file. This
is for growing project files to real project files that can be loaded
and selected from the GUI. And decoupling project files from the
directory they reside. So you can put project file in any directory,
load it and it checks paths listed.
GUI reads per-project settings (automatically deallocated classes) from XML project file. The project file format is described in projectfile.txt. Example project file is added for gui.
See also forum discussion at:
https://sourceforge.net/apps/phpbb/cppcheck/viewtopic.php?f=3&t=46