Bumps version to 0.25a1.
changelog: Rewords robots.txt filter bypass.
conversation.py: Removes deprecated function.
Implements --restrict-file-names. Closes chfoo/wpull#62.
Saves filename to database to allow converter to work consistently.

Closes chfoo/wpull#45.
converter.py: Uses filename field instead of PathNamer.
database.py: Schema change: Adds filename field.
engine.py: set_status accepts kwargs.
processor.py: WebProcessor uses new root_path argument.
writer.py: save_document() returns filename.
engine.set_status(): Use filename keyword instead of kwargs.
changelog: Fixes typo in save_document.
writer.py: Refactors safe_filename and fixes Python 2 support.
testing/badapp.py: Allows path with queries.
engine.py: Adds URLItem.child_url_record()
processor,hook: Renames _should_fetch. Checks filters before inserting.

Re: chfoo/wpull#70
Implements --quota. Closes chfoo/wpull#3.
Implements --warc-max-size.

util.py: Adds truncate_file().

Re: chfoo/wpull#26
terse_options.rst: Updates for quota, warc-max-size, restrict-file-names.
Merge branch 'issue/70-many-links-hang' into develop
changelog.rst: Adds point about not adding URL to database if skipping.
Refactors WebProcessor.__init__ to use parameter object pattern.
Implements --content-on-error. Closes chfoo/wpull#37.
processor.py: Logs PhantomJS scroll actions as JSON dump.

Closes chfoo/wpull#49.
Adds command scripts. Closes chfoo/wpull#50.