Added possibility to give format for files output by HISTOGRAM
Merge branch 'v2.0' of github.com:plumed/plumed2 into v2.0
Same sequence of Gaussian numbers with different compilers

This fixes #23
Notice that it slows down (with icpc) generation of Gaussian numbers
by a factor 2.5. I think it is better now to have reproducible regtests.
Fixed simplemd to write output file

It was a longstanding (unknown) bug!
I added reference output files for all the simpledmd
regtest. This will allow to distinguish bugs in plumed
from Lyapunov effects in trajectories.
Merge branch 'v2.0'
Fixed calculation of neighbors index with pbc

I think the way pbc were applied was not correct (Fix #19).
Added flag to check if dlopen is available
Added regtest for LOAD
Merge branch 'fix-19' into v2.0
Merge branch 'v2.0'
Minimal fix for #25

With this fix plumed crashed when using ADAPTIVE=DIFF and replica
exchange.
Merge branch 'v2.0'
check if the file exists on molinfo
check if the file exists on molinfo
corrects the previous bugged commit
Merge branch 'v2.0'

Conflicts:
	src/core/SetupMolInfo.cpp
added a check over the sigma when diffusion
Merge branch 'v2.0'
Added SIGMA_MIN and SIGMA_MAX keywords to MetaD

with this keyword you can limit the range of sigma when using the
adaptive Gaussian scheme.
Merge branch 'v2.0'