add pgup/pgdn keys and fix history in multiline edits
Scroll to correct position when fetching more lines

Fixes #406
embedded content: check if scrollIntoViewIfNeeded vendor method is available
Merge pull request #455 from ailin-nemui/ifneeded-conditional

embedded content: check if scrollIntoViewIfNeeded vendor method is available
Merge pull request #448 from glowing-bear/fix-scrolling-fetchMoreLines

Scroll to correct position when fetching more lines
Merge pull request #445 from ailin-nemui/up-down-pgup-pgdn

add pgup/pgdn keys and fix history in multiline edits
Bufferlist design attempt
Merge pull request #457 from torhve/compactbufferlist

Compact bufferlist
[themes] make nicklist width fixed on mobile UI so text doesn't get cut off
Merge pull request #453 from ailin-nemui/nicklist-width

[themes] make nicklist width fixed on mobile UI so text doesn't get cut off
Revert "Bufferlist design attempt"

This reverts commit 2475ad2c61cb5f835ef6ef3d4d7234ce82cb9dee.
Create dark theme by extracting theme settings from glowingbear.css

* Remove style.css as those values should be themable as well.
* Update urls in index.html to link to dark theme by default
Provide a way to change the theme in the settings

* Selected theme is dynamically loaded
* Preferred theme is stored in the settings.
* Default theme = dark
Add light theme
light-theme: darken most colors by 50% and add it to theme manager
[light theme] make the background lighter
[light theme] set highlight colour to something readable
[light theme] improve readability of default grey colours
[light theme] make default text color readable
[light theme] fix the notification colour again