force contextual help links to open in new window

- add 'target=_new' attribute to help links
Merge pull request #595 from strongloop/feature/inject-target-into-help-links

force contextual help links to open in new window

#527
add watchdog popover directive

- repurpose help popover for watchdog popover
- add directive to pid selector (only visible if isMetrics flag is true)
add watchdog popover directive

- remove duplicate style
add watchdog popover directive

- hide watchdog for now
add popover for menus

- add flag to hide on page click
- otherwise use mouseenter/mouseleave to hide menu
- add global pageClick event