gui: introduce SettingEntry class to handle the setting entries explicitly
gui: Moved initialization code from the main module to the tab class where it belongs
img: Added a 'disabled' image to the 'start button in the acquisition window
gui acquisition: add support for presets

basic preset computations

detect when the preset combobox value changes

change the highlight mechanism to be done from the acquisition part

listen to the context menu event instead of right_click event for the reset menu
Merge branch 'master' of vpn.delmic.com:odemis

Conflicts:
	src/odemis/gui/cont/acquisition.py

seemed to be only white spaces conflicts