Missing filename in cairo_ps_surface_create args
Merge pull request #46 from ntd/bugfix1

Missing filename in cairo_ps_surface_create args
cairo.Status.to_string() must accept cairo.Status

Having cairo.Status as input argument instead of ti.int allow
to_string() to accept both symbolic name and number value.

Added test case to check name-value equality.
Merge branch 'upstream' into devel