Remove dependence on Iconv module
Remove dependence on Iconv module

So as to depend on one less module, perform the UCS-2/UTF-8 conversion using
a pair of custom methods written in C. The code would be easy to extend to
handle UTF-32 when/if I move to it.

This change doesn't break any of the existing specs, but I'll be adding
additional specs to specifically test the conversion methods and confirm
that they appropriately reject invalid input (unlike the old wrapper
functions these ones are public).

I also intend to add some benchmarks in a future commit to compare
performance with the old implementation.

Signed-off-by: Wincent Colaiuta <c76ac2e9cd86441713c7dfae92c451f3e6d17fdc@wincent.com>

barnaclebarnes/wikitext,wincent/wikitext,wincent/wikitext,geni/wikitext,barnaclebarnes/wikitext,barnaclebarnes/wikitext,geni/wikitext,geni/wikitext