For the sake of maintenance of Scintilla (future update), we try to not modify Scintilla project, or at least minimize its modification.
Hence the compiling boost part is shifted to Notepad++ project.
Fix#11014, close#11485
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
ArkadiuszMichalski