Make listener,logger,unicorn static libs on unix:!mac

The only Linux app is the scrobbler, so there's no point in creating
private shared libraries for it.  Now linux users don't need to
fiddle with LD_LIBRARY_PATH.

Yay.
On linux, rename the scrobbler binary to lastfm-scrobbler
Add icons for the scrobbler
Add a desktop file too
'make install' now works on linux

e.g. qmake PREFIX=/usr/local; make install
Include translations when running make / make install
Merge pull request #16 from jstamp/install

Install