Dynamically create DAMASK_ROOT and DAMASK_BIN

by sourcing this script.

also documents the changes to .bashrc if one wants to 
'install' DAMASK permanently

damask_env.sh

@@ -0,0 +1,11 @@
+#!/bin/bash
+
+# it would be nice to set the variables
+script_location = `dirname $0`
+echo I am here: $script_location
+
+export DAMASK_ROOT=/nethome/$USER/DAMASK
+export DAMASK_BIN=/nethome/$USER/DAMASK/bin
+export PATH=${PATH}:${DAMASK_BIN}
+export PYTHONPATH=${PYTHONPATH}:${DAMASK_ROOT}/lib
+export LD_LIBRARY_PATH=${DAMASK_ROOT}/lib/fftw/lib:lib/acml4.4.0/ifort64_mp/lib:lib/acml4.4.0/ifort64/lib:${LD_LIBRARY_PATH}