Spike out --move-warc-to.
Merge branch 'yipdw-move-to' into issue/135-warc-move
Rename "--move-warc-to"→"--warc-move", move all WARCs and CDX, unit tests

Renames to --warc-move for consistency. Implements moving all WARCs and
the CDX file to given directory. Adds check in options.py to check
existing directory. Implements unit tests for WARC recorder move_to.

Re: chfoo/wpull#135
app.py: Fix up warc move arg.
WARCRecorder._move_file_to_dest_dir: Add docstring.

[ci skip]
changelog: Add bullet about --warc-move.

[ci skip]
Merge branch 'issue/135-warc-move' into temp1

Conflicts:
	doc/changelog.rst
Merge branch 'temp1' into develop

Conflicts:
	doc/changelog.rst
	wpull/builder.py