* Drawing and put_figchar methods now can handle utf8 chars.

* Bind caca_render_canvas function.
* Add example font.

the future.

* Add example figfont

* Fixes #85

- Ignore key events when XFilterEvent returns true
  - Do not set key to 0 when it is over 128

* get_canvas method now return Python Canvas object.

* Add exceptions for missing methods.

a lot of software (wrongly) assumes that int32_t is the same as int.