The browser lets the user pick one or more directories in a convinient
GUI browser. The initial directory list is read from a string
(separated by colons) and the resulting list is written back to the same
string (again separated by colons).
Note: The work was initially done by Jonathan Gordon, however I changed
it substantially so I claim autorship.
This selector is going to be used for autoresume and database scan folders.
Change-Id: Id1d3186dad783411eb5c6056ce93f5b6123c7aa0
