Avoid calling libtool to link every single test case, by building just one
binary from all the sources.
This binary is then given the task of choosing tests to run (based on user
selection and individual test requirement), forking each test into its own
process and accumulating the results.
During the cairo summit it was decided that this API is to freetype-
specific to be in the general cairo interface for now. This will
likely come back again soon as a cairo_ft-specific interface.
In order to correctly report the error back to the user during the
creation of a scaled font, we need to support a nil object per error.
Instead of statically allocating all possible errors, lazily allocate
the nil object the first time we need to report a particular error.
This fixes the misreporting of an INVALID_MATRIX or NULL_POINTER that
are common user errors during the construction of a scaled font.
Partial revert of commit 0086db893c.
This is a follow to the earlier commit that allowed creation of scaled
fonts using a NULL font options (by interpreting the NULL as meaning
use the default options) to reflect the comments made by Behdad
(http://lists.cairographics.org/archives/cairo/2008-January/012714.html).
The intent is that the public font options getter/setter API has similar
defensive behaviour to that of the core objects - i.e. do not overwrite
the nil object and if the object is in error then return the default
value. For the indirect use of a NULL/nil font options (e.g. creation of
scaled fonts), then an error should be returned rather than crashing.
