Removes some unnecessary code from config dialog.
We have no need to store a reference to the processor
array anymore.

Signed-off-by: Jim Teeuwen <jimteeuwen@gmail.com>
Refactors some of the processor code. Renames SourceEditMode
to ProcessorMode and changes the enum values to be more
descriptive. We have currently have three distinct modes in
which a processor can operate:

* SINGLE_USE: This is a processor which is run only when
  a document is opened. This is intended for processors
  perform a one-time change to the document. E.g.: `gocode`,
  which initializes the SourceCompletion api from GTKSourceView.
* BEFORE_SAVE: Runs when the user saves the document,
  but before the document is written to disk. This is
  intended for processors which rewrite the buffer
  contents. E.g.: `go fmt` and `go imports`.
* AFTER_SAVE: Runs when the user saves the document
  and it has been written to disk. This is meant for
  processors which only read document contents and
  require the most up-to-date version of it.

Signed-off-by: Jim Teeuwen <jimteeuwen@gmail.com>
Removes unnecessary debug print.

Signed-off-by: Jim Teeuwen <jimteeuwen@gmail.com>