add in test case
some changes in SymbolicSample.cpp(not finished yet)
In operator+ for ScalarMatrixFunc class,if only putting *rhs.derivativeFuncVal in the constructor, program will fail. To temporally skip the problem I introduce a zero MMF func and put func+*rhs.derivativeFuncVal in the constructor which will leads to extra space and slow down the program which need to be fixed.
Merge branch 'calculator_issue'

Conflicts:
	tests/SymbolicSample.cpp