Fix ctags for complex Cython type declarations

Cython allows the use NumPy arrays on a C level. In that context, a
typical return type declaration could be e.g. "cpdef
numpy.ndarray[dtype=double, ndim=1] name". This now generates a tag for
the function. Previously, the equal sign prevented that.
Add test for complex datatype Cython tag generation
Merge branch 'aeberspaecher/cython/ndarray-fix'