Add a browse button which opens a popup panel containing the
list of projects and their descriptions to the Settings >
Watched Projects screen. Selecting a project from the list
(single clicking it) adds it to the add project text field,
and opening a project from the list (double clicking it) adds
it straight to the watched list.
Bug: issue 204
Change-Id: Ifb24da3ba870b8d4fee09a0d8b7a1960b4ea6c98
1d9a6526ba