Heavy LdCanvas refactoring, some modifications to ld-types.
It just wasn't possible for me to further work with an old,
2000 lines long file without shuffling everything around
at the same time.
This is required for gtkdoc-scangobj. So far it's much like it's been
before, the main differences are that source files are in two directories
from now on and the build process has two stages.
Přemysl Eric Janouch