Merge pull request #1 from conejo/master

Small fix to IsNumeric regex
Added nuget package file
Added Encryption Providers for AES and SHA256 / SHA512

Removed unused project
Added Readme.md
Added Tests
Renamed Tests project to be OffTheShelf from OffTheSelf

Rewrote most of Encryption, removed interfaces and added more generic
ones
Added Method to CryptoProviderFactory to pass in key and iv

Added latest Nuget package