#84 C++11 new using semantics

[Kevin Brodsky]

Here is a patch adding support for this new C++11 syntax:

using <Type> = <type definition>;

Apart from some template subtleties, this is totally equivalent to a typedef, at least as far as ctags is concerned. Thus, it is considered that in a SCOPE_USING (that I've added), if we have an assignment, it is a TAG_TYPEDEF. By checking for the assignment, we avoid mistaking a using namespace/using ns::id clause for a typedef.

Enjoy!