A table lookup is now used when that will be faster than SIMD.
Characters are now given as an expression of the form "or(<a,>z)" to the search functions. This allows the user to somewhat hand optimize, especially when more functions than just "or" get implemented.
Moved uniconv to cstring, as it currently only handles converting D string to C wchar* or char*.
Added char* handling routine to fast.cstring. It is a no-op for compile time known constants.