The eq operator would only work for some types and put the
interpreter in an error state if passed objects it didn't
know how to compare. It would also not compare strings
by value nor allow strings to be compared to names.
This patch makes any two objects comparable.
Add a CairoScript interpreter library and use it to replay the test output
for the CairoScript backend. The library is also used by the currently
standalone Sphinx debugger [git://anongit.freedesktop.org/~ickle/sphinx].
The syntax/operator semantics are not yet finalized, but are expected to
mature before the next stable release.
