Renamed & moved path vars to own function

Our continuing mission: to move stuff out of MainWindow.__init__ and
kalpana.py.
Moved get_paths() out of the class
Moved plugin creation to its own function
Stupid import bugs in pluginlib SQUASHED
Moved plugincmd-init in terminal to own function
Moved UI creation in MainWindow to own function
Minor restructuring in MainWindow.init()
Moved key shortcuts to own function