Speed up things in running chasers

Scene: Use a map instead of a list (way faster search, auto sorting)
Doc: Do not search two times in the fixture map when fetching a fixture
scene::insertStartValue -> only one search in the qhash
qlcfixturemode: change containers from list to vector
doc::fixture(quint32) speed up

add a hashmap container for quicker fixture access
Create a new signal to separate functionChanged from functionNameChanged
fix update of vccuelist in case of step function name change
fix foreach loops
Doc: only one container for fixtures
unittest fix: little differences between list and vector
unittestfix : function nameChanged signal
Merge pull request #368 from plugz/speedup

Performance improvements during continuous Function changes