Merge Edit and View modes of launcher

[dasupradyumna]

Idea

Since the appearance of edit and view modes are quite simliar, it makes sense to merge both the Launcher modes into a single mode. It seems intuitive to view a config, and edit it immediately. Having a separate mode for that purpose feels excessive. The fact that view mode does not have a lot of distinct actions also helps this case.

This idea requires further design considerations.

[dasupradyumna]

Dim empty fields (using highlight) in this combined edit-mode so that active fields stand out in contrast to empty fields.
Refer to #52 for more details.