WIP: implements fwide from wchar.h

have implemented fwide, but now need to go through: http://pubs.opengroup.org/onlinepubs/009696699/functions/xsh_chap02_05.html

to make sure the following is true in the rest of relibc:

Byte input/output functions cannot be applied to a wide-oriented stream, and wide-character input/output functions cannot be applied to a byte-oriented stream. The remaining stream operations shall not affect and shall not be affected by a stream's orientation, except for the following additional restriction: