Dish: allow config.misc.lastrotorposition to be used elsewhere

As suggested by Dima73
Solve anomaly with radio zapping after changing radiobouquet
Rename numberZap to numberSelection in ChannelSelection

As this better covers what it exactly is doing.
Dish: Commit fix for mistake from previous Dish.py patch

see: http://openpli.org/forums/topic/34648-dishpy/
As suggested by Dima73
Merge branch 'master' of git://git.code.sf.net/p/openpli/enigma2