emacs: allow the user type C-c C-l during completion.
emacs: removed the character limitation for AC.
emacs: refactored the completion functions.
emacs: made customize for variables and reorganized the variable definitions.
emacs: fix a lot of docstrings.
emacs: customize menu entry.
emacs: introduced merlin-default-flags.
Merge remote-tracking branch 'github/locate-compl' into emacs-dev

Conflicts:
	emacs/merlin.el
emacs: added var merlin-ac-prefix-size.
emacs: fixed merlin-try-completion when changing the value of merlin-ac-source.
emacs: use start-file-process to handle remote executions (thanks to Valentin Gatien-Baron)
emacs: fixed copyright.
emacs: set limit of "long answer" to 10k.
emacs: merlin-seek can now send seek exact/end commands.
emacs: fixed merlin-send-command-async.

The callbacks were called in the temporary buffer created by tq. It is
weird that tq does not handle itself to restore the original buffer.
emacs: when using "quiet" way of telling merlin, check for the errors before the current phrase.
emacs: cleaned merlin debug output.
emacs: replaced call to end-of-buffer by goto-char.
Merge branch 'emacs-dev' into experimental
emacs: made next/prev-phrase have the same behaviour as tuareg equivalent.