Exit with code 3 when nikola fails before task is run.

Using exit code 3 similar to what do-it uses.  Fixes #1455.
Merge pull request #1457 from getnikola/return-code

Exit with code 3 when nikola fails before task is run.
freezegun update, take three.
and a livereload update for good measure
fix #1459 -- apply filters to all tasks

Signed-off-by: Chris “Kwpolska” Warrick <kwpolska@gmail.com>