Caesar.decrypt and OneTimePad.decrypt now takes encoders, constructors now takes no arguments
Updated documentation
Updated example program simpleencryption to utilize the new common interface.
Updated monoalphasubstitution and transposition

to use new common interface
Fixed bug which broke tests
Minor rework, now constructor takes encoder as argument
Refactored monoalphasubstitution and transposition modules so that constructors now take encoder classes as parameters
Minor bugfix in OneTimePad.encrypt where the wrong amount of arguments were supplied to generto keyGen
Fixed simpleencryptions bug

Erronous use of the EncoderClass when generating the key
Fixed minor bugg in example program
RSA: Added lots of new stuff

Refactored RSA interface and added blockmodes.py in preparation for
symmetric encryptions.
Also addad a new example program
Fixed some errors in docstrings and doctests