Add .gitignore with .DS_Store to the linter template.
Add option to set tempfile_suffix to '-', which disables linting for all but load/save and save only lint mode.

This is to accommodate linters like javac that must work on a real file.
Allow a default to have no prefix, which means it can be used as a setting but will not be passed in the args.

Useful when linters need args in non-standard formats.
Allow file-only linters to lint after saving the file in background mode, but clear that linter's marks otherwise.
As a precaution, ensure there is a message.
Fixed enabling of the Lint This View command.
Bump version.