This is a big CL overhauling the webconsole implementation.
Important changes:
* WebSockets are now used to communicate with the server. This makes incremental updates very easy to implement. "gevent" and "gevent-websocket" pip packages have to be installed in order for websockets to work. Updated setup.py accordingly.
* Javascript files are now better structured.
* Support for object actions is added. Actions are registered by type. Elements with available actions are highlighted in the UI. Clicking on them brings context menu.
* Full support for free format text, tables, sections, progress events and error messages is now implemented.
* AngularJS-specific optimizations implemented (see fast-repeat directive).
* UI now mostly doesn't rely on formatstrings. The objects are meant to be rendered via renderers that are registered by type.

R=scudette@gmail.com

Review URL: https://codereview.appspot.com/129080043