shaper: fix control character filtering
shaper: fix control character filtering

Correct off-by-one error and add 0x200c-0x200f range. This range
is compromised of explicit direction and join marks.

Fixes issue 54
Fixes issue 55

pigoz/libass-ct,xbmc/libass,grigorig/libass,Akemi/libass,libass/libass,MrSmile/libass,blinkseb/libass,rhlee/libass,blinkseb/libass,torque/libass,rhlee/libass,astiob/libass,tgoyne/libass,astiob/libass,mwgoldsmith/libass,Akemi/libass,tgoyne/libass,mwgoldsmith/libass,tgoyne/libass,stps/libass,grigorig/libass,richardpl/libass,pigoz/libass-ct,stps/libass,Akemi/libass,xbmc/libass,torque/libass,libass/libass,stps/libass,richardpl/libass,ShiftMediaProject/libass,torque/libass,sanyaade-g2g-repos/libass,sanyaade-g2g-repos/libass,MrSmile/libass,ShiftMediaProject/libass,sanyaade-g2g-repos/libass,blinkseb/libass,rhlee/libass,mwgoldsmith/libass,richardpl/libass,pigoz/libass-ct