Patch from O01eg fixing #1308 http://forum.vcmi.eu/viewtopic.php?t=721
Helper functions for enabling/disabling smart vector memeber serialziation. [doesn't really save writing but adds consistency]

git-svn-id: http://svn.code.sf.net/p/vcmi/code/trunk/@3436 4dfc6b2a-8b31-0410-aa91-d6c70e3ac834