* Fix drag+dropping bookmarks when not in reverse order (the new default)

* Fix bookmarkFoldersReversed appearing as checked in the settings page even though it's suppose to be unchecked by default.

* Add options to disable reverse order of bookmark folders.
* Detect Dark mode (Firefox Settings > Website Appearance). Note that the default about:newtab page in firefox detects if the titlebar theme is dark instead of this setting.
* Clear search after pinning a folder.
* Show search group even when there's no results.
* Update GUI when a bookmark has been added/removed/moved in other windows or with Firefox's GUI.
* Cleanup icon SVGs and CSS.
* Rastered logo SVG to png and fill with firefox addon green color.
* Workaround GitHub favicon in dark mode since it's black on black.

* Render pinned folders in the desired config order every time. Previously it would draw whatever bookmark folder was loaded first.
https://github.com/Zren/NewTabRecentBookmarks/issues/4
* If only the bookmark title or url was changed, the bookmark is updated without a full reload.

* Fix the default background favicon fill appearing on editing bookmarks. background-color=none is not valid CSS, background-color=transparent fixes the bug
https://github.com/Zren/NewTabRecentBookmarks/issues/3
* Fetch the favicon from the cache as soon as the bookmark is loaded rather than waiting for everything to load first.
* Add debug code for testing clearing the firefox favicon cache. I've noticed that the GitHub's favicon is white (on a white bg) when the browser is in dark mode. I'll be looking into how to detect dark mode to detect theme changes to clear the cache. I'll also look into creating a dark CSS theme.

* Added drag and drop to rearrange columns.
* Added delete bookmark button when editing a bookmark.