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.
CA-110509: Impossible to create LVHD over iSCSI SRs with more then one iSCSI target IP

When passing multiples IPs on the target list, when printing entries for the
wildcard option we compose a string this way
IP1,IP2,..,IPn:PORT
The IPs can be in IPv4 or IPv6 format but the last colon is always
a delimiter for the port.
The parse_IP_port function is not suitable in this case (it needs to be modified, anyway),
so we simply split the PORT from the rest of the string: the latter is kept as it is.