Do not retrieve debugger command from ABI as that causes mismatches
when several toolchains of the same ABI are present.
Use indexes in the debugger dialogs.
Polish tooltip.
- Make showWarningWithOptions actually show the details.
- Show errors from multiple engines as separate messages.
- Remove 'enabled' option from CDB (handled by toolchain config now).
- Show ABI as tooltip in debbugger toolchain chooser.
Add combo box listing toolchains with debuggers to start external,
attach and core.
Another attempt at streamlining engine detection:
Split in detection functions that first collect a list of
available engines by preference, then remove disabled and
wrongly configured engines and use the remaining best.
matching. checkconfiguration is now the central place where
engine detection and config check takes place.
Rubber-stamped-by: hjk
