[notmuch] Introducing notmuchsync

[Sebastian Spaeth]

> What needs improvment?
>  - Support for the "T" (delete), "F" (flagged), "D" (draft) tags/flags.

Having just finished this feature, I herewith declare notmuchsync to be version
0.0.1 :). It works for fine for me, I use it to sync the "FTDS" Maildir flags
(corresponding notmuch flags: 'unread','flagged','draft','delete'), as
well as for periodically pruning mail files that are marked as 'delete'.

Let me know if you have issues with it.

The 2 most urgent issues are: 
 - Move read files from 'new' to 'cur' folder. At what point is that
   moving typically done in Maildir? When the user has actually looked
   at the mail?
 - chunked output parsing (9k messages went through fine on my laptop,
   but I doubt that 200k msg would)

Sebastian