Add support to embed videos.
Raise better IOError if a connection file is not found

when starting parallel.Client

Example:

    IOError: Connection file u’~/.ipython/profile_default/security/ipcontroller-client.json' not found. Is a controller running?
Add is_complete request and reply to messaging infrastructure
Expose IPython machinery for testing code completeness
Document is_complete messages

Also, bump message spec version
Use the more powerful signatures module to display function argument signatures. In particular this works better for functions wrapped with functools.wraps (at least on Python >= 3.4)
Four possible states for completion reply, & indent hint
Set protocol version number back to 5.0

Bumping to 5.1 wasn't necessary, because we're still finalising 5.0
(thanks @minrk)
Allow widget views to be loaded from require modules

This required refactoring things that create widget views to use
callbacks instead of return values.
Make changes suggested by @jdfreder
Fix logic
Put callbacks for create_view and create_child_view in options

And add errback support
Clean up some JS code
Remove superfluous error checking
Fix ansispan() to ignore stray [0m
Use more yellowish color for ansiyellow
Test IPython.utils.fixConsole() (really ansispan())
Improve handling of cursor_start and cursor_end for completions.

Improve handling of cursor_start and cursor_end for completions.

Improve handling of cursor_start and cursor_end for completions.

Fix handling of end != cursor_position

Fix handling of cursor offset and handle end <= start.

Fix handling of cursor offset and handle end <= start.

Reinstate extra whitespace

More whitespace reinstating

Still more whitespace

Finalwhitespace

Add a guard on start

Fix logic for end > cursor_pos

Another ws add

WS tweak

WS again
support buffers in comm messages

- add buffers arg to comm Python api
- support binary websocket messages when buffers are present
- reimplement utf8 in javascript, because javascript is the best
s/unserialize/deserialize