Fix user profile settings

References #3810, #3944

- Fixes several small visual bugs with the user settings page
- Changes `.settings-subview-header` to use a clearfix instead of `overflow: hidden;` (fixing style issues in #3944)
Handle EADDRINUSE

no ref
- Show a human readable message on EADDRINUSE
Merge pull request #3990 from halfdan/handle-addrinuse

Handle EADDRINUSE
Remove active class from buttons.

refs #3989
- Remove active class from {{#link-to tagName="button" ..}}
Merge pull request #3991 from halfdan/3989-active-class

Remove active class from buttons
Improve keyboard support

issue #3964
- added :focus selector to improve keyboard support in modern browsers
- added :active selector to improve keyboard support in old IE
Merge pull request #3995 from JamieKnight/keyboard-support

Improve keyboard support
Post Settings Menu - Step 1

closes #3936
- Implement new PSM
- Hook up close action
- Automatically close when view is destroyed
- Close on click and when pressing ESC
Merge pull request #3965 from halfdan/3936-psm-1

PSM Step 1
Prevent horizontal scroll on content list

Closes #4000

- Adds `overflow-x: hidden;` to the content list & preview wrapper
Merge pull request #4003 from PaulAdamDavis/no-right-scroll

No right scroll
Merge pull request #3960 from PaulAdamDavis/fix-user-settings-page

Fix user profile settings
[WIP] Wire up new mobile nav

References #3810

With GUI2, there's now a number of places to open the mobile navigation menu. This handles those clicks.