New features on memory safty and regression test

In this new release, we have first introduced a new feature of regression test,
so that the simulation results of test cases will be compared with previous computed results.
This will eliminate hidden bugs which do not blowup the simulations.
The second updates in the release is the enforcement of Resource acquisition is initialization (RAII),
so that memory leaking which often due to new raw pointers will be avoided.
For this, the ownership of objects are explicitly defined with the help of smart pointers.
Since these smart pointers are only involved in object constructors,
the usage and efficiency of raw pointers (as observers) for computation was not influenced.

You are welcomed to test and report issues.