This is the first implementation of a theme manager. It’s a rebased and
revisited version of #792.

Now uses the same as in the deck editor

+ added sound setting page
+ added sound setting icon
+ moved sound settings from interface settings

Added master volume

+ added master volume slider.
+ volume can be changed by sliding bar or by using the spin box
+ Preview of  volume will be played when dragging and releasing bar.

Added checks for qt4

Qt4 does not have support for setting the volume without some lengthy
work around, I have disabled volume control for qt4 users and have
mentioned that "Master volume requires qt5".

Updated sfx

+ removed all old sfx
+ added new end step and tap sound
+ tap/endstep sound has a timer on it to prevent spamming
+ test sound engine will now use endstep sound

Made end step sfx softer

end step felt too harsh

Added player joined sound

+ added a sound for when a new player joins a room

Updated

Was missing a sound when a player joins

Made end step softer

Made end step even softer

updated sound again

+ Removed unused buttons
+ remade button art
+ fixed crash with font colors/replays
+ removed unused timestamp label in replay

Buddies will now be seen as stars in the chat

From https://github.com/joielechong/iso-country-flags-svg-collection.
(States that flag images are public domain)

Added translation of some new strings and svg file of South Korean flag.

Flag of South Korea is from
http://commons.wikimedia.org/wiki/File:Flag_of_South_Korea.svg

Please note that I don't feel that the search bar needs to be skinned by
users, hence why it is not part of the large css-skinning project. I
also feel that given the PR #416 a new search bar with highlight the new
search functionality.

Updated the look of the search  bar:
+ larger, curved edges
+ changes color when has focus
+ search icon built into search
- removed "Search For" text in lieu of search icon

Removed some unused resource files.

added option to ignore unregistered users in chat; switched UserList data storage to QMap to speed up lookups; issue #28 fixed