When comparing paths in python we have to use normcase.

Chromium requires relative paths for output-dir and
for generator-output. Also output-dir is expected to
be a subdirectory of generator-output.

This now allows building on windows without running
qmake in recursive mode.

Change-Id: Ie0f9965c1fbfd63eb3cb9c360b29f210128a5c3e
Reviewed-by: Andras Becsi <andras.becsi@digia.com>