rcairo/rcairo — pull request #31 by cosmo0920 (2014-11-03 11:12:27+00:00)
Title: fix compilation error not found `cairo-quartz-image.h` in OS X

`cairo-quratz-image.h` is not always installed.
Simply installation cairo in OS X with Homebrew as follows:

% brew install cairo

Homebrew's cairo Bottle is not fully enabled quartz feature.
So, it is not installed `cairo-quartz-image.h`.
This lack of existence of `cairo-quartz-image.h` causes following error:

```log
compiling rb_cairo_surface.c
rb_cairo_surface.c:58:14: fatal error: 'cairo-quartz-image.h' file not
found
# include
^
1 error generated.
make[1]: *** [rb_cairo_surface.o] Error 1
make: *** [all] Error 2
```

Instead, following installation is also installing `cairo-quartz-image.h`

% brew install cairo --without-x11

It seems that it needs check `cairo-quartz-image.h` existence before it include `cairo-quartz-image.h`.