[Shotwell] dropping Windows support

[Adam Dingle]

For the last several releases, it's been possible to build Shotwell for 
Linux (in its full glory) or for Windows (a limited alpha version 
missing support for publishing, camera import, printing and possibly 
other features).  With the upcoming 0.8 release we're planning to drop 
Windows support entirely: it will now be possible to build for Linux 
only.  Running on Windows was never a primary goal for Shotwell, and the 
Yorba team simply does not have the resources to keep the Windows port 
alive at this point; we'd rather focus on improving Shotwell for the 
open source world.

If anyone cares about the Windows port and wants to volunteer to 
maintain it, speak up now and we can keep the associated code alive in 
our source tree with your help.  Otherwise it will likely disappear with 
the 0.8 release or soon afterward.

adam