Fix a build error with OpenMPI 1.4.x

The function ADIOI_PLFS_Feature() shouldn't be defined when
compiling PLFS with OpenMPI 1.4.x.
Merge pull request #215 from zhang-jingwang/master

Fix a build error with OpenMPI v1.4.3
Merge branch 'master' of github.com:plfs/plfs-core into 2.4dev
Fix a build error with OpenMPI 1.4.x

The function ADIOI_PLFS_Feature() shouldn't be defined when
compiling PLFS with OpenMPI 1.4.x.
re-added 1-n information to plfsrc.5in that was accidently removed in an earlier merge
Merge branch '2.4dev' of github.com:agtorre/plfs-core into 2.4dev
Merge pull request #222 from agtorre/2.4dev

Merging of other branches + fix to plfsrc.5in