vchoi_fork

[svn-r27916] Re-merge of r27884-27891 from the trunk + bugfix for a few
H5S recursive functions where an aliased pointer was
incorrectly set too early.

Tested on: Ubuntu 15.04 (Linux 3.19 x86_64) w/ gcc 4.9.2
           serial and parallel (w/ MPICH 3.1.4)