Nattka

- process-bugs: fix not ignoring resolved dependencies.
- include copyright line updates in keyword updates.

- multiple new search filters: category, security, arch, sanity-check,
- documentation now covers usage, with detailed explanation of options,
- improved support for handling dependencies, esp. when bugs are listed
explicitly,
- 'apply' command has been revamped to behave more like getatoms.py:
it now prints machine-usable output and is focused on working
for a single arch.

- default not to update bugs (require explicit --update-bugs for that)
- support running read-only without Bugzilla API key
- support quiet output and logging to a file
- filter package keywords to match CC list when arches are CC-ed already

Initial testing release with functional 'process-bugs' command.