[issue #470 - session specific include paths] initial setup in dialog

For a new session the paths from the general preferences are added by default.
This can then be edited by the user.
[issue #470 - session specific include paths] documentinfo

Including the session specific include paths to the jobinfo.
[issue #470 - session specific include paths] make it optional
[issue #470 - session specific include paths] additional buttons
Indent problem
Merge pull request #474 from PeterBjuhr/sessions

Session specific include paths - wip