gui: plotcanvas update
gui: Migrated view legend to its own module in gui.comp
gui: renamed mscviewport module to viewport
gui: split plot canvas into a base class in components and an inherited one in the dblmscopecanvas module
gui: canvas module renaming
gui: small documentation fix
gui: removed superfluous test case
gui: label positioning fix and test refactoring
gui: fixed merge conflict
gui: use new goal image for mirror alignment

mirror alignment procedure expects to _not_ use the lens. So the image is flipped
and twice bigger.

Also note in the SVG file how we got to the right dimensions.
Merge branch 'master' of vpn.delmic.com:odemis
test: rename again test file, so that it ends with _test.py

Test files must end with _test.py to be automatically executed during global test suite
gui: tweaking for mirror alignment translation controls

X axis needs to be inverted for image to go the same direction

separate step size for X/Y, as they are usualy quite different values