[PATCH 0/6] Readd IDLE support again

[Ethan Glasser-Camp]

Hi guys,

Please find the following six patches which take the next steps
towards readding IDLE support.  There are at least the following known
problems:

- Hooks may not be sufficient for prompt handling of IDLE responses.
  For example, there's no hook that lets me run "notmuch new" after
  processing an IDLE response.

- nametrans may not be supported correctly (I haven't tried this).

- IMAP IDLE<->IMAP IDLE doesn't work.  I have a couple of patches for
  this, but nothing complete.

- There's an outstanding bug report that IDLE only works "once" for a
  given sync -- meaning that after one IDLE response is processed, no
  further IDLE request is made.  I have not been able to reproduce
  this, but I wouldn't be surprised to find bugs here.

These patches are also available on my github fork of offlineimap,
branches readd-idle-REBASE and readd-imap2imap-REBASE.  These branches
will, as the name implies, be rebased until merged, so be warned.