Make grad an allocatable rather than a static array.
The array grad(mxat, mxat, 3) in the function esolan caused memory
problems when the number of residues was chosen large even when the analytic
solvent calculation isn't used.
Now, the array is allocated dynamically and only when the function is called. It
is deallocated when esolan is done.
git-svn-id: svn+ssh://svn.berlios.de/svnroot/repos/smmp/trunk@23 26dc1dd8-5c4e-0410-9ffe-d298b4865968