This patch will replace the common/ directory with the spice-common
project. It is for now a simple project subdirectory shared with
spice-gtk, but the goal is to make it a proper library later on.
With this change, the spice-server build is broken. The following
commits fix the build, and have been seperated to ease the review.
v2
- moves all the generated marshallers to spice-common library
- don't attempt to fix windows VS build, which should somehow be
splitted with spice-common (or built from tarball only to avoid
generation tools/libs deps)
v3
- uses libspice-common-client
- fix a mutex.h inclusion reported by Alon
