added two new input arguments to GenMeshMatlab.m for node file name and elements file name. also now displays file generation time and number of nodes and elements generated.
created new function NodeElemVol.m to calculate the volume of nonlinear meshes
made calcNodeVol.py for calculating node volumes of nonlinear meshes. started adding checks to field2dyna.m to determine whether or not calcNodeVol.py should be called
currently working version. added two input arguments - one for elements file name needed to calculate node volumes, second input argument for forcing node volumes to be calculated. corrected syntax errors in calcNodeVol.py
replaced code that created and read from node-element mapping file with another dictionary
made command-line arguments optional with default values of nodes.dyn, elems.dyn, and NodeVolume.txt
made corresponding change in field2dyna.m to match new command-line arguments of calcNodeVol.py
added input argument to exist function so that only files are searched through, and not directories
generated NodeVolume files now have a slightly more descriptive name. also fixed mistake with exist function.
Merge branch 'master' of github.com:Ningrui-Li/fem into Ningrui-Li-master

Conflicts:
	field/field2dyna.m

Conflicts included:

1. Inputs to field2dyna (numWorkers was dropped)
2a. dynaField input: numWorkers was hard-coded to 4
2b. dynaField output: FIELD_PARAMS was added
3. New function at end of field2dyna