refactor(cockpit): move engine selection to directive

- increase loading speed of application by inlining header and
  moving engine selection to directive

Related to CAM-1004
refactor(cockpit): overhaul cockpit css

- refactor sitebar open/collapse directive
- simplify/drop dashboard/process-instance/process-definition css
- cleanup app/common css declarations
- apply minor fixes to variable instance tab

Closes CAM-1004
chore(cockpit): reorganize jquery / add jquery-ui

- move jquery and plugins into designated folder
- add jquery-ui for draggable support
- update jquery to latest version (1.10)

Related to CAM-1004
impr(cockpit/layout): add resizable columns to cockpit layout

- cockpit instance and process definition views contain resizable colums
- layout is slightly cleaned up

Related to CAM-1004
chore(merge): merge from upstream
fix(cockpit/links): fix some links between apps