adding the proc apm_supported_callback_types for the new package callbacks. Making apm_load_packages take arguments to make it optional to source libraries and queries (only load tests, needed for acs-tcl)
setting upgrade status for a message key to deleted if the en_US message is deleted. This is unfortunately another example in the I18N code where we are assuming the presence of the en_US locale and that translation is done from this locale.
making sure message keys with upgrade status of deleted are not exported to xml files, important fix: write xml files in utf-8 if the specified charset is not supported by tcl, correcting some log statements