A simple test to track down some platform-specific differences we were seeing in freetype font rendering inside of matplotlib.

Thanks to Thomas Robitaille (@astrofrog) for setting a lot of the theoretical groundwork for this.

BUILD: make

RUN: ./freetype_test [charcode] [fontfile] [ptsize] [dpi] [stretch] [output_file]

    e.g.:

    ./freetype_test Vera.ttf 97 20 500 8 test

    To match what matplotlib does, set stretch to 8.  To turn off
    the effect of stretching (to see if it matters) set stretch to
    1.

    This will output two files, test_grey.pgm (greyscale antialiased)
    and test_mono.pgm (monochrome bitmap).