gui: change default step sizes for SPARC alignment

From tests at AMOLF, should be better default values. X needs to be _smaller_ than Y.
gui: optimized repetition point rendering
gui: point repetition refreshing added
gui: fix time of acquisition being displayed in UTC

time is saved in UTC, but must be displayed according to localtime.
Merge branch 'master' of vpn.delmic.com:odemis