Added internal lapack/blas

Adapted from GROMACS
Merge branch 'v2.0' into internal-lapack
Merge branch 'v2.0' into internal-lapack
Fixed configuration file)
(suggested by Toni Giorgino)
Merge branch 'v2.0' into internal-lapack
Merge branch 'v2.0' into internal-lapack
Fixed script to re-import lapack/blas
reimported lapack/blas from gmx 4.6.4

(no change, just a statement in the license)
blas and lapack on single file

(compiles faster)
Possibility to use external lapack/blas

One can either use external libraries with:
CPPGLAFS=-D__PLUMED_EXTERNAL_BLAS and -D__PLUMED_EXTERNAL_LAPACK
and
DYNAMIC_LIBS=-lwhatever_appropriate

or, with no flags, use internal libraries.

The two flags are independent (one can e.g. use external blas
with internal lapack)
Both internal and external lapack works now

I fixed it so that it *Really* works with both internal and external
lapack/blas. The only drawback (I could not do it better) is that
both lapack and blas should be either internal or external.
Reversed logic

Now needs PLUMED_INTERNAL_LAPACK/BLAS to use the internal version,
and by default uses external one. This makes it more coherent with
master branch.

Thus:

One can either use external libraries with:

CPPGLAFS=-D__PLUMED_INTERNAL_BLAS -D__PLUMED_INTERNAL_LAPACK

uses internal ones, whereas:

DYNAMIC_LIBS=-lwhatever_appropriate

uses external ones.
Merge branch 'master' into internal-lapack
Doc and changelog

Ready for merge. Nothing should change with existing Makefile.conf.