Conditions scopes that had "else" were not handled properly.
The "else" condition should be expanded to its proper negative full
form.
Also every condition "piece" should be wrapped with parentheses before
being passed to sympy simplification, to be sure that boolean
operator precedence is applied properly.
Refactored the code a bit to make it easier to read.
Change-Id: I4726845b867f93c3afbc9362cdce1cd063ccff63
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>
0798ed8a83