Refactoring of print_info() to print_line().
New version of print_info().

This time the method prints [INFO] statement in front of the message.
Adds the beginning of user documentation.
Changes color of INFO messages to blue.
Adds message type warning (WARN) in yellow.
Adds message for the case no Git is found on the system.
Model: config object gets initialized with ConfigParser.ConfigParser() now.
Introduces start and end markers in the encrypted file.
ConfigParser is used now to read in encrypted file.
Splits up methods into smaller chunks.

This helps readability a lot and the code is easier to understand.
Updates user documentation.