qbs-config: Understand JavaScript for all types.

The current code understands JS maps, but not lists of maps etc, which
is certainly unexpected. So allow JS literals for all types.
Additionally, simple sequences of characters are still interpreted as
strings, so users are not forced to quote in the common case.

Change-Id: Ifd345b86cd730fb1d394dbf90e9357fed86edd97
Reviewed-by: Joerg Bornemann <joerg.bornemann@digia.com>
qbs-config: Get rid of the "CfgGet" command type.

This one is silly. It has the same functionality as "CfgList", but takes
a different code path and can format values differently.

Change-Id: If77023bc9960ea545e3cfdc11b763e0f32a98409
Reviewed-by: Joerg Bornemann <joerg.bornemann@digia.com>
fix "Failed to compare version" warning on OS X

Change-Id: I38eadf5070ba0789c2865f9d4c31bd7f70c82059
Reviewed-by: Fawzi Mohamed <fawzi.mohamed@digia.com>