CP-5443: Make sm compile with different Python versions.

Use proper include directory.

Signed-off-by: Frediano Ziglio <frediano.ziglio@citrix.com>
CA-99235: Keep trying to remove the tag forever

In the error handling path of VDI.activate, if the connection with the
master is lost, the slave cannot remove the tag from sm-config. When the
connection is restored, the VDI is left in undefined state. To avoid
this we keep trying to remove the tag until we succeed (the connection
with the host has been restored).
Merge pull request #7 from tmakatos/CA-99235

CA-99235: Keep trying to remove the tag forever
Merge pull request #6 from freddy77/python_version

CP-5443: Make sm compile with different Python versions.