Added new feature Traffic disruption

Added a number of classes supporting the new feature also done
some minor bugfixes to GUI
Hardcoded the colours for each Tube line

Tfl changed the colour scheme to "web safe" in their weekend tube
disruption feed so now the colours are hardcoded for this weekend GUI
elements as well.
Minor fixes in the GUI

Fixed changelog and changed 2 ScrollDecorator -s to
VerticalScrollDecorator
Changed parser/fixed GUI blocking issue

GUI thread was blocked due to Xml parser using too much resources,
it now has its own thread and no longer blocks GUI.
Instead of QXmlSimpleReader Trafic disruptions feature now
uses QXmlStreamReader.
Traffic disruptions feature's GUI was also improved,
 namely Refresh Widget now works correctly, and Refresh now only available
while not downloading or parsing. Pulley menu now also shows busy while
downloading or parsing.
Fixed issue with closing TrafficPage

Fixed issue when user would close TarfficPage while a filter is set,
it would keep the old filter even though SearchField is empty.
Also bumped version to 0.3.0
Added Licence information to source files

Pasted liscence into new source files.
Added documentation

Added documentation to new code + minor fixes in code