The flag in the socket has clear semantics now -- it tracks whether corresponding context was closed, it doesn't track whether zmq_close was called on the socket itself

termination of pipe via delimiter message could stuck when no data were read from the pipe (because connection wasn't active) -- fixed

* maint:
  values of RATE, RECOVERY_IVL and SWAP options are checked for negative values

* maint:
  Version number incremented to 2.0.10
  NEWS updated for 2.0.9

Conflicts:
	builds/msvc/platform.hpp
	configure.in

* maint:
  Update .gitignore
  doc: Add 0MQ version to XHTML11 backend footer
  build: Generate ChangeLog in 'make dist', ZIP automatically

Thanks to Matt Weinstein for the suggestion.

Change 'make dist' to generate the Git ChangeLog file, that way it doesn't
have to be manually updated nor kept in Git which causes unnecessary work.

Also change 'make dist' to invoke 'dist-zip' automatically to generate a
ZIP as well as a .tar.gz.

Thanks to http://live.gnome.org/Git/ChangeLog for the inspiration to
automatically generate ChangeLog.

* maint:
  Broken device numbering reverted
  assert on malformed messages
  forwarder and streamer devices handle multi-part messages correctly
  improved null checking in zmq_term

Conflicts:
	AUTHORS
	include/zmq.h
	src/zmq.cpp

* maint:
  zmq::select_t, zmq_poll(): assert if FD_SETSIZE reached
  zmq.h: Fix typo and use of C99 comment

Conflicts:
	src/zmq.cpp

Ensure that 0MQ does not attempt to call select() on more than FD_SETSIZE
file descriptors.