This commit adds the following new functions to the cairo-ps API:
cairo_ps_surface_dsc_comment
cairo_ps_surface_dsc_begin_setup
cairo_ps_surface_dsc_begin_page_setup
Many thanks are due to Michael Sweet who provided invaluble guidance
during the design of this API.
It is hoped that with this API in place, basically all printer control
that is likely to be desired to be performed with cairo PostScript
output is now possible.
This commit augments the ps-features test to exercise the new API.
Add a new cairo_ps_surface_set_size which can be used to produce a
PostScript file consisting of pages of various different sizes (or
orientations).
Also add a new test (ps-features.c) for testing this and subsequent
ps-specific function calls.
