Minor fixes
Merge branch 'nobuff-shmem' of https://github.com/Ruyk/gromacs into nobuff-shmem
Merge branch 'nobuff-shmem' of https://github.com/Ruyk/gromacs into nobuff-shmem
Merge branch 'nobuff-shmem' of https://github.com/Ruyk/gromacs into nobuff-shmem
PME: Fixed bugs with more than 256 cores

The shmem_getmem routine produced weird problems when going
beyond 256 cores, it is replaced by a shmem_float_get in this commit.
Also, the size of the count vectors is now symmetric across all ranks,
by setting the size always to the number of PEs rather than using nslab.
This enables the usage of 2D decomposition in the PME computation.
Recovered call to put_with_off

A bug introduced in a previous commit incorrectly commented-out the
put_with_off function call in domdec_network.c. This is fixed in this commit.
Increased number of shmalloc checks

Large executions seems to require a larger number of checks to stabilize the
size of the buffers. The constants MAX_SAME  and MAX_CHECK has been increased
to reflect this fact.
shmem_float_sendrecv_off size comm. restored

The interchange of the buffer size in the shmem_float_sendrecv_off routine
was removed incorrectly, and it is restored on this commit.
Increased the MAX_SAME constant in constraints

Increased the MAX_SAME constant in domdec_con.c
Merge branch 'nobuff-shmem' of https://github.com/Ruyk/gromacs into nobuff-shmem

Conflicts solved in src/mdlib/domdec.c