Implement double click on project manager to open a file.
On branch master, changes to be committed:
	modified:   src/mainwindow.cpp
	modified:   src/mainwindow.h
Set flag so the project list is not editable by the model view.
On branch master, changes to be committed:
	modified:   src/projectmodel.cpp
Implement file recognition to automatically select a highlighting language.
On branch master, changes to be committed:
	modified:   languages/c.xml
	modified:   languages/cplusplus.xml
	modified:   languages/octave_matlab.xml
	modified:   languages/python.xml
	modified:   src/scintillaeditor.cpp
	modified:   src/syntaxhighlightmanager.cpp
	modified:   src/syntaxhighlightmanager.h
Implement basic session saving and loading
On branch master, changes to be committed:
	modified:   src/main.cpp
	modified:   src/mainwindow.cpp
	modified:   src/mainwindow.h
Implement saving of project list to session settings.
On branch master, changes to be committed:
	modified:   src/mainwindow.cpp
	modified:   src/projectitem.cpp
	modified:   src/projectitem.h
	modified:   src/projectmodel.cpp
	modified:   src/projectmodel.h