style for /subreddits page and new icons

- added style for /subreddits page. similar to link listing
- added icon for "not an approved submitter"
- added icon for "last edited comment"
- added comment bubble icon (from userstyle) to subredit's icons
- removed menu icon (was originally for RES' macro dropdown)
- remove `.side` from subscribe button selectors
- move style of tabs inside `.menuarea` from _inbox.scss to _list.scss
remove subscribe button's text shadow on explore page