allow session_id to be undefined when starting kernel channels
update font-awesome
genereate css
remove redundant 'responsive-utilities' from style.less

it's already included in bootstrap.less
Merge pull request #6691 from minrk/rm-bs

remove redundant 'responsive-utilities' from style.less
Merge pull request #6685 from minrk/allow-no-session-id

allow session_id to be undefined when starting kernel channels
Merge pull request #6669 from SylvainCorlay/font_awesome_update

Font awesome update
Merge branch 'qtconsole-completion' of https://github.com/blink1073/ipython into qtconsole-completion
Fix handling of end != cursor_position