== and != for complex types in new lily_class_func.{c,h}. Fixes #19.

I also pulled the gc marker functions from lily_gc.* into lily_class_func.*
I decided to do this because these special functions are only pulled by
lily_seed_symtab, so it seems rather silly to have other modules load the
gc marker functions.

Added a new test to sanity.ly, as well as a new failing test. A new exception,
ErrRecursion, will get raised in comparions are used against something
circular.