Urlscan

* PEP8 fixes/modifications
* Update tld list
* Fix up arrow bug. Closes 66
* Add optional config file for editing/adding palettes.
* Simplify palette variable to only used values. Cycle through available palettes
* Merge branch 'runtime_palette_switch' of https://github.com/machinedgod/urlscan into machinedgod-runtime_palette_switch
* Fix crash when BROWSER not set. Closes 60, Fixes 63
* Don't handle mouse events. Fixes 65.
* Hitting 'b' key now switches palettes
* Allow https URLs for images
* Add 51. Execute arbitrary expression for URL in place of opening browser.
* More fixes for 48. Refresh screen after text browser use
* Fix 49. Deduplication display issue.
* Fix 50. Detect and add ability to remove escape char \ from URLs.
* Fix 48. Prevent loading thread from affecting screen when using
* terminal browsers.
* Add g/G as top/bottom keyboard shortcuts. Fix 47

* Update minimum urwid version
* Type number to jump to URL
* Bugfix

Fix tag mismatch in setup.py

* Fix 27 (URLs in markdown links)
* Tweak email address recognition
* Add ability to toggle context view
* Cleanup, commenting, add keyboard hints in the header
* Add shortening and toggling shortening of URLs
* Restructure URLChooser for current urwid best practices
* Update tlds list
* Replace AttrWrap (deprecated) with AttrMap
* Highlight selected URL. Fix 17
* Implement 21 (Option to remove duplicate URLs)

Bugfixes