build, glusterd: Add liburcu to build system

2015-02-23T12:35:37+00:00

This patch adds liburcu related checks to the build system and updates
the spec file to require 'userspace-rcu'.

liburcu >= 0.7 is required to build GlusterFS, but 0.8 and above is
preferred. For cases when liburcu 0.7.x is the available version, some
function definitions (currently just one) from liburcu-0.8.6 have been
made available in /contrib/userspace-rcu/.

This change was developed on the git branch at [1]. This commit is a
combination of the following commits on the development branch.
  a5cd6bd Add userspace-rcu checks to configure.ac
  fe5ced3 Add URCU libs to glusterd libtool flags
  1e43302 Add local definition of cds_list_add_tail_rcu for
          liburcu-0.7
  98da755 Move local definition of cds_list_add_tail_rcu into contrib
  8c44dfd Update spec file to include userspace-rcu0466e33 Rename
  rculist-additional.h to rculist-extra.h
  947c7b3 Add rculist-extra.h to dist
  19f32ad Address review comments 9605/1

[1]: https://github.com/kshlm/glusterfs/tree/urcu

Change-Id: Ifbb617d0dacce8fa01214f894badb9d8cdcaf56f
BUG: 1191030
Signed-off-by: Kaushal M 
Reviewed-on: http://review.gluster.org/9605
Tested-by: Gluster Build System 
Reviewed-by: Atin Mukherjee 
Reviewed-by: Niels de Vos 
Reviewed-by: Krishnan Parthasarathi 
Tested-by: Krishnan Parthasarathi

glusterfs.git/contrib/userspace-rcu, branch experimental

build, glusterd: Add liburcu to build system