Added a module to parse logical equations

Added a module to parse logical equations and convert it to BinPy compatible Gate level functional statement.

Sample Input:

`print eqnParse('~((((~A)&B&C)^(~A))&E&F&G)')`

Sample Output:

`NAND(G,F,E,XOR(NOT(A),AND(C,B,NOT(A))))`

This can be used along with eval to yield the respective gate object.