Windows: Fix --windows-disable-console and --debug were not working together.
Windows: Fix, derive dlltool path from the actual MinGW64 g++ being used.

* Otherwise MinGW32 preceding it in the PATH could win, but would create
  a library that mismatches the arch.
New hotfix release.
Merge branch 'hotfix/0.5.4.1'
Merge tag '0.5.4.1' into develop