fix python implementation of calc_text_pos and calc_width, tests pass.
fix python implementation of calc_text_pos and calc_width, tests pass.

--HG--
branch : python3

zyga/urwid,bk2204/urwid,inducer/urwid,ivanov/urwid,hkoof/urwid,drestebon/urwid,bk2204/urwid,tonycpsu/urwid,wardi/urwid,urwid/urwid,mountainstorm/urwid,foreni-packages/urwid,drestebon/urwid,rndusr/urwid,harlowja/urwid,tonycpsu/urwid,bk2204/urwid,mountainstorm/urwid,ivanov/urwid,douglas-larocca/urwid,wardi/urwid,hkoof/urwid,rndusr/urwid,harlowja/urwid,wardi/urwid,zyga/urwid,inducer/urwid,Julian/urwid,foreni-packages/urwid,douglas-larocca/urwid,harlowja/urwid,Julian/urwid,westurner/urwid,tonycpsu/urwid,rndusr/urwid,urwid/urwid,zyga/urwid,inducer/urwid,westurner/urwid,ivanov/urwid,urwid/urwid,mountainstorm/urwid,westurner/urwid,Julian/urwid,foreni-packages/urwid,hkoof/urwid,douglas-larocca/urwid,drestebon/urwid