MSVC 2013 compatibility: missing includes.
MSVC 2013 compatibility: no Unicode char/string literals.
MSVC 2013 compatibility: no rvalue references for *this.
MSVC 2013 compatibility: needs explicit type specification for addTests().

This is the most annoying thing so far.
Utility: removed redundant CORRADE_UTILITY_EXPORT.

Causes errors on MSVC, not needed anywhere else.
Merge branch 'master' into compatibility