WIP: Removed excessive condition check on char eligiblity.
WIP: Jump right to later half of conditions when _mode isn't true.
WIP: Extracted more condition checks to dict.
WIP: Combined two dicts into single dict. Simplified the condition checks.
WIP: Removed excessive condition check.
Added back unicode string spec to condition check in _convert_to_full_width (self, c).
Issue #14: Merge branch 'refactor_convert_to_full_width' into 1.7