corrected potential nbnxn SIMD memory issue

A fixed size array on the stack was declared with one element
too few. Probably this never caused trouble with 64-bit builds,
but it might have caused trouble with 32-bit builds.

Change-Id: I4dad0a7a9e80f5d27ac6ee7e4383082db654481a
Fix incorrect variable name in documentation

Change-Id: I312e3886ebc692f2331ac2f9a612d530b5d4914c
Fix DD load balancing bug with GPU sharing

The recent DD load balancing fix which solved the issue of incorrect
imbalance measure with GPU sharing (ba8232e9) addressed GPUs with
incorrect indexing. This caused out of bounds indexing in the GPU ID
query function. The query function also had a bug in the error checking
which allowed the incorrect indexing.
Now also mdrun -nb cpu -gpu_id ... is allowed, which before would give
a fatal error.

This commit addresses both issues; fixes #1385

Change-Id: I2800f610b873da92afe78bbfd869258f378ba2d7
Fixed return value of gmx_mtop_bondeds_free_energy

The return value was always true, which was harmless, since it 
could only cause a small performance hit of useless sorting.

Fixes #1387

Change-Id: I088a3747ddb3517fbb5e416b791bd542bd49fed2
Merge branch 'release-4-6'

Conflicts:
	src/gromacs/legacyheaders/topsort.h
Resolved in favour of comment change in release-4-6

Change-Id: Ib930277635cdd260c136ab9b3e02809682587252
Merge "Merge branch 'release-4-6'"