Updated such that messages are heap-allocated.

  NOTE: This makes a big memory leak each time the subset of
 messages changes.

  This is a transition as I rework the code as per issue #3.
  Correctly retrieve messages.

  We had a bug where the /new/ or /cur/ portion of the filename
 wouldn't work.
  Updated the way that messges are handled.

  Read messages are now marked as such, which causes a bug, as
 expected.  Issue #3 is real and will be a pain to fix.
  Added limiting for folders, and unified search-forward
  Formatting/comment updates.

  No functional changes.
  Fixed error in syntax.

  I'd ommitted a closing bracket.
  global_mode( xx ) will downcase xx.

  This allows for looser setting.
  s/clearStatus/clear_status/g
  Minor comment + compose updates.

  compose() now inserts the appropriate From: address, and respects
 EDITOR if it is set.
  Allow the maildir to see if it matches a filter.

  Rather than doing this in the binding file.

  This is the same as CMessage.
  Rename filter -> matches_filter.

  This matches CMessage.
  Messages are now persistant.

  This solves the problem of reading a message causing it to
 become removed from the display.

  Closes #3.
  Show the selected folders if no messages are visible.

  This is a neatness thing :)
  Updated to reflect current state.
  index_limit now does substring matching.
  index_limit("new") works again.

  I'd mis-handled this case so that it was attempting to match
 the formatted header.