Visual Studio 2013 Preview compile fixes:
* 0 is not convertible to std::function, nullptr should be used
* std::ref(rand) is not convertible to function<int()>, used lambdas (why we dont just pass "rand" ? )
* CFunctionList needs to be constructible from nullptr
* move constructor for CMapInfo (Visual cannot generate them :( )
* #ifdefed some stuff that is not needed anymore since cmath is updated with C99 stuff
* using std::make_unique instead of our vstd implementation

CSelector: 
* introduced a class in place of typedef
* Having an overloaded && || operators over sth that is convertible to bool… Wasn't a good idea after all. Purged the operators, replaced  with And/Or methods (chaining-style).
* constructor that is present only when constructing from class or function (SFINAE). std::function has an implicit converting constructor from T causing ambiguities (even if the overload would cause compile error in the body)

git-svn-id: http://svn.code.sf.net/p/vcmi/code/trunk/@3433 4dfc6b2a-8b31-0410-aa91-d6c70e3ac834