adding the apm_get_package_files proc for fetching files of certain types of a package. The idea is to rely on the filesystem rather than the info files/db for file listings. Made the install more verbose again for packages as I wanted to see why my installation didn't work. We could use the apm_dummy_callback if we make sure that as soon as there is an error inoformation is presented to the user. It is also good to show progress during installation
Making apm_source update the apm_library_mtime variable (just like the analogous proc for xql files does). Making installation log much less information to the browser (changing from apm_ns_write_callback to apm_dummy_callback). Moving initialization of util_memoize cache to happen before first package is installed (fixes bug 242).