Bug fixes

• Lock files are cleaned up robustly. Previously there was a race condition
  resulting in blocked subsequent edits, due to a lingering lock file.
• --del will ignore requests to delete a parameter in a non-existing section
  (unless --existing is used). Previously it failed citing the missing section.

New features

• The --existing option takes parameters to give more control over what needs
  to pre-exist. So you can specify for example that a file needs to exist,
  but any items within it are created as needed.
• A new --verbose option was added to indicate on stderr wether the
  request resulted in a config change or not. This can be used to
  determine whether to restart programs etc.

Changes in behavior

• Files are created by default if missing, unless --existing is specified.

Improvements

• Protections against creating unparseable ini files were added.
• stdin can be parsed just as with normal files.
• File writes are avoided if there are no changes to the config.