mount/fuse: add mount-option "enable-ino32" for the native client

By default the GlusterFS-native client uses 64-bit inodes. Some 32-bit
applications can not handle these correctly. Introduce a client-side
mount option "enable-ino32" which causes the FUSE-client to squash the
64-bit inodes into a 32-bit value.

Change-Id: I7544010a27b7eb2d3b9fadb84ed934e4e7dff21e
BUG: 850352
Signed-off-by: Niels de Vos <ndevos@redhat.com>
Reviewed-on: http://review.gluster.org/3886
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Anand Avati <avati@redhat.com>
doc: Add the "enable-ino32" native-client mount-option

Change-Id: I9568a39c3e3497f94c098cdac0331d0a25122e35
BUG: 850352
Signed-off-by: Niels de Vos <ndevos@redhat.com>
Reviewed-on: http://review.gluster.org/3887
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Anand Avati <avati@redhat.com>