include Poole-Frenkel detrapping with the frequency model (not examined)

- ENH : enhance the method for updating RSH for detrapping, add the Poole-Frenkel emission rate for frequency model
- ENH : waring when energy decrease due to Poole-Frenkel is too large
- NEW : add the method to consider Poole-Frenkel effect with frequency model in trapping solver
minor revision based on last version

ENH : add invalid parameter name message
major revision on the parameters read-in class

- NEW : read new parameters
- CHG : change the name of some existing parameters
begin to consider the triple-cell structure

- NEW : add new class/file for triple-cell structure
- ENH : enhance FDContact class, add workfunction to the contact class
- ENH : enhance FDRegion class, use vector to store regions other that region map. region vector can deal with invalid requirement
- ENH : enhance FDElement class, the adjacent element of vertex can be set during setting the vertices belonging to the element
- CHG : some naming change in Material class
begin to test triple cell domain

- NEW : add the method to read domain parameter from parameter file in TripleCells class
- NEW : add the class filling the adjacent vertices of each vertex
- CHG : some adjustment of the previous methods
debug the class for triple cell structure

- FIX : fix a bug in getting contact with name
- FIX : fix a bug in reading parameters
- NEW : new method to get vertex id with given (ix, iy)
revision during building the triple-cell structure

- FIX : fix the method to check if a vertex is valid
- NEW : now, if the vertex lacks only one element, it is boundary vertex.
revision for solving Poisson only

- NEW : add the method to read substrate information
- ENH : enhance solver pack to check simulation structure
debug the solver pack

- CHG : change on the method to instantiated regions in SimpleONO class
- NEW : add new method in FDDomain to obtain trapping layer material
- FIX : fix a bug in TrapToGateTunneling solver, where the tunnel tags of all the interface vertices are set during solving tunneling problem of each slice
the SolverPack can run again with triple-cell structure

- CHG : remove the use of layer type name
- ENH : seperate the methods for setting trap distribution and trap occupation
- FIX : fix a problem in tunnel layer, use gate voltage in contact property instead of gate voltage in global control
start to change the method to determine the tunneling direction in tunneling solver

- FIX : fix a bug in building the SimpleONO structure
- NEW : use new method to calculate fermi energy at the two sides of the tunneling barrier
change the method to determine tunneling direction in TrapToGateTunnel solver
enhance the TrapToGateTunnel solver to consider the current tunneled from gate to the trap layer

- NEW : add a new material parameter, electron DOS mass, to be used in the calculation of tunneling current. DOS mass is different from the tunneling mass of certain material, also add DOS mass to physical property
- ENH : enhance the TrapToGateTunnel solver, current solver can consider the tunneling-in and tunneling-out situation
- ENH : solver pack can read the tunneling in current density in from gate
test on retention of triple cell structure

- NEW : set the trap occupation under gate2