Simplify & Generalize stepping code, introduce stubs for reverse
debugging. When user switches to another thread than the
event-triggering one in a stopped inferior, explicitly tell
the engine to continue that one.

Improve fixDumperResult to fix missing types (out of scope items)
and call it from expandPointerDumpable.

Plus some minor reformattings.

too

done with Erik Verbruggen

The behaviour is expected to happen after d9d39ab2.

Useful for simple context menu items.

It's easier this way for the unique naming.

Default creation type implementation are still missing for cmake and
generic projects.

Instead use the BuildConfiguration class methods directly.

Builds, but I'm pretty sure it doesn't *work* :)