Fix static linked libdynd

Turns out the ${CMAKE_CURRENT_SOURCE_DIR}/ in the thirdparty
lib were necessary, added a note about why.
dynd_complex<double> failures on MSVC 2010, relax test precision slightly
Newline at the end of special_vals.hpp
Try a tighter relative error bound on the special function tests
Rename metadata -> arrmeta  across the codebase

This is to more clearly distinguish the arrmeta (array metadata)
from other types of metadata used in other contexts.
Add a function to the base_type class for providing the option nafunc
Boilerplate for option[string]
Add a type pattern matching routine