[IMP] SASS support, dependency fetching

 * Fetch asset dependencies - currently for jQuery, Compass and qTip2
[IMP] Replace generate.sh with fab task
[IMP] Added env vars, pythonbrew check/install
[IMP] Added fab task to generate docs

 * Gets run on tarball generation time
[IMP] Compass files properly loaded
[IMP] Improvements in fabfile

 * File delete confirmation;
 * Option to use system nodejs;
 * cleanup task;
[FIX] 'uiTabs' -> 'ui-tabs'
[IMP] Installing underscore with setup_deps
[FIX] Use webassets for git, because of PySCSS plugin

 * Fix not available in official release;
[IMP] Create all minified files in /static/assets

 * Instead of having them spread across htdocs;
[FIX] 'uiTabs' -> 'ui-tabs'
[FIX] Missing underscore submodule
[FIX] Missing 'git submodule init'
[MIN] Add flask and werkzeug to requirements
[IMP] Use werkzeug dispatcher middleware
[IMP] Add flask app stub, make it runnable
[IMP] Add .wsgi file for the flask app
[FIX] Use correct Flask root_path

Thanks to indico being a namespace package flask sometimes fails at
determining the package root path correctly
[DEL] Broken/unused htdocs files
[IMP] Add routes for all the old htdocs functions