Added support of escape characters

[wadeking98]

Added functionality to support escape characters when forging ciphertext. \\ -> \ \n -> newline \t -> tab \r -> carriage return ...etc \x00 -> HEX<00> (nullbyte) \x01 -> HEX<01> ...etc

example: padre -u "http://vulnerable.com/login?token=$" -enc "Encrypt\r\n\xffM\te"

[glebarez]

hello. can you rebase on master please, so that CI tests can pass