fix some sync issues

- better error message when upload fails
- don't show success message on error
- fix 'unable to find server' accidentally being catchall
fix "free variable 'mw'" error (#284)
add link to add-on forum in error
surplus newline typo
fix field outline overlaps with other fields
Merge pull request #19 from frostschutz/newline_typo

surplus newline typo
Merge branch 'master' of github.com:dae/anki
Merge pull request #20 from frostschutz/editor_field_outline

fix field outline overlaps with other fields
Merge branch 'master' of github.com:dae/anki
Merge remote-tracking branch 'dae/master' into flake
when given base on cmdline, get abspath
Merge remote-tracking branch 'dae/master' into flake

Conflicts:
	aqt/downloader.py
	aqt/sync.py
Clean up of changes.
Re-clean.
(I guess i pressed the wrong button in meld. Wanted to just clean the changes.)
Fix another warning (non-problem) spotted by flake8