1. Scintilla and Lexilla intermediate files are created in the same folder as NPP build file (`bin.i686.build` or `bin.x86_64.build`), but in subfolder `_lexilla.build` and `_scintilla.build`. I added `_` char at the beginning so these folders are always at the beginning. If you prefer a different name or location it can be change.
2. Stop build and dispaly error message when someone run "outside build" (use `-f` option) and source path has any spaces. It won't work anyway, so it's worth stopping the process and give a clear message.
3. Add new phony target `sciclean` and `lexclean` for deleting Scintilla or Lexilla intermediate files separately.
4. Change `_` to `|` for temporary replacement of space characters when detect proper shell. Char `_` is allowed in paths and should not be used for that purpose.
5. Add one more condition for `MAKELEVEL` variable to prevent unnecessary second calls to Scintilla and Lexilla makefile.
6. Update also `nppSpecifics_mingw.mak` file to works with above change.
Now we don't have to remember to clean up the previous files when we switch to different compiler (32-bit or 64-bit) or when we generate a debug version.
Fix 10991, close#11450