as suggested by Gareth

I added a PEOPLE file containing list of authors and a script
(src/header.sh) which applies the Licence to all the source files.

It can be applies multiple times (it automatically deletes the present header
and replace it with the new one). Thus, to change the header, edit header.sh
and execute it.

Now the input can be
 RMSD REFERENCE=frame_1.dat TYPE=OPTIMAL SQUARED
this is usefult to reproduce initial path cv behaviour
without passing through an additional function

in terms of the residues for the chains for which one wishes to calculate the distances
from the alpha helical secondary structure.  For these reasons I had to adjust the PDB
parser so that it reads in atom symbol, resdiue and chainID data.  I then I have an
ActionSetup class (MolInfo) that can read and store the data on the various chains inside the
pdb file.  I have that you can calculate the distances from the secondary structure using either
DRMSD (like plumed 1.0) or using Davide's RMSD class.  This required a very small change to Davide's
RMSD class.

Many checks on size() transformed in checks on empty()
(suggested by cppcheck)

Mostly unused variables, implicit conversions, etc

I tried to also add error messages, at least when I knew the meaning
of the assertion...

I eliminated some compilation dependencies among header files.

I think that "FromPDB" is implicit in the fact that the
first argument is of type PDB)

Now should be really working! Remember: good dinner+beer help a lot!

Initial seed for weighted alignment. Need further debug.

I removed scale method from Vector. I think it is
more readable to use the *= operator.

So that the enum is hidden inside the RMSD class
and syntax is more consistent with other classes

Still it is only the RMSD *without* best alignment