Added document lines that name the default device drivers.

Also:
- Changed some <htmlurl> tags to <url>.  Now, those links will show their URL addresses (in addition to their names) in info and text pages.
- Added some Atmos-specific function names to its document.
- Fixed some punctuation syntax.
Fix error which slipped in in '-L' command line parameter handling.
Merge pull request #101 from groessler/something_to_pull

Fix error which slipped in in '-L' command line parameter handling.
Merge pull request #100 from greg-king5/default-drivers

Added document lines that name the default device drivers.
Added doc install target.
Harmonized usage of "KB" and "cc65".
Merge remote-tracking branch 'upstream/master'