QbsProject: namespaces and Qt 5 connects in build configuration

Change-Id: I4e86a2549f58c2f5ddf00b609598e426de2d3128
Reviewed-by: Christian Stenger <christian.stenger@digia.com>
Utils: MacroExpander API cosmetics.

Make const-correct, add convenience function for commandline parameter
expansion.

Change-Id: I12c3651e4e7b8a0a9319d1dfbea676b622b1a41a
Reviewed-by: Tobias Hunger <tobias.hunger@theqtcompany.com>
MacroExpander: Set the "legacy" global project values directly

This currently duplicates a few lines, but lets us address the
"better" context-specific case properly later.

Change-Id: I0e8249823d4f6d6e8f3a5f4c86b2cb0410ae3195
Reviewed-by: Tobias Hunger <tobias.hunger@theqtcompany.com>
Move uses of ProjectMacroExpander closer to build configuration

All static functions, can live closer to related code.

Change-Id: I54c5680256c78f1d09b4bee3e8843b2f4350b75a
Reviewed-by: Tobias Hunger <tobias.hunger@theqtcompany.com>