Patch from Jeff Muizelaar <jrmuizel@nit.ca>.  Changed to allocate
        glyphs using gmalloc.

        * poppler/CairoOutputDev.cc (CairoOutputDev::drawString):
        Implement drawString instead of drawChar. This change should
        make clipping to a text path work and has a performance
        improvement. Currently the code is a little ugly because we
        can't concat matrices to cairo without losing our current font.

        * poppler/CairoOutputDev.h (CairoOutputDev::useDrawChar):
        Tell Gfx.cc that it should use drawString instead of drawChar.