Improved handling buildings with mode "auto":
* they will properly processed (new creatures will be added if dwelling, spells learned if mage guild, and so)
* transitive dependencies are handled (A makes B build, and B makes C and D)

git-svn-id: https://vcmi.svn.sourceforge.net/svnroot/vcmi/trunk@3384 4dfc6b2a-8b31-0410-aa91-d6c70e3ac834