second part of c++11 update. gcc 4.5 and VS 2010 are no longer supported
- BOOST_FOREACH -> for
- replaced several boost classes with std (e.g. unordered)
- removed gcc-4.5 workarounds
- ran clang c++11 migration tool to detect some cases:
- - pointer initialized with "0" to nullptr
- - replace for with iterators with range-based for
- - use auto in some situations (type name specified twice, avoid long iterators type names)

git-svn-id: http://svn.code.sf.net/p/vcmi/code/trunk/@3432 4dfc6b2a-8b31-0410-aa91-d6c70e3ac834