Extension to the mutt upstream.

1.5.22-rc1:

+ use git and github rather than hg to maintain source code

+ virtual folders based on notmuch queries
+ merge sidebar patch
+ merge index-color patch

+ <change-vfolder> command
+ <vfolder-from-query> command
+ <modify-labels> command to set/unset notmuch tags
+ <modify-labels-then-hide> command to set/unset notmuch tags and hide email
  from the current view
+ <quasi-delete> command to delete message from mutt, but don't touch message
  on the disk
+ <entire-thread> command to add to the current list of the messages all 
  messages that belongs to the same thread as the current message
+ ~Y EXPR  pattern modifier for notmuch labels for limit, tag-pattern, 
  delete-pattern, color etc.
+ virtual-mailboxes <desc> <uri> [...]  to specify list of the virtual mailboxes
+ virtual_spoolfile = <boolean> to use the first virtual mailbox as a spoolfile
+ tag-transforms <tag> <transform> to transform tag name to another name
+ tag-formats <tag> <format sequence> [ ...] to define tag specific formatting
  sequence for $index_format
+ nm_record = <boolean> to add sent emails (mutt record) to notmuch DB
+ nm_record_tags = <comma delimited list> to specify tags for nm_record
+ nm_open_timeout = <seconds> to specify timeout for notmuch database
+ nm_default_uri = <uri>  the default URI to connect notmuch
+ nm_hidden_tags = <comma delimited list> to make some tags invisible for mutt user
+ nm_exclude_tags = <comma delimited list> - messages tagged with these tags 
  are excluded and not loaded from notmuch DB to mutt unless specified explicitly
+ nm_unread_tag = <name> to specify unread messages
+ nm_db_limit = <num> to specify notmuch query limit
+ nm_query_type = <threads|messages> to specify what to load from DB
+ vfolder_format = <string> to specify vfolders brower entry format
+ %g and %Gx index_format and pager_format formatting sequences