Add global variables for package
Function for debug messages
Debug messages if zip is not from PLEXOS
More debug messages
Debug message in log_parser
Debug messages in  new_database, add_extra_tables
Debug message in correct_length check
Add another message, in case there are problems
Debug message only show if in debug mode
Typo in debug message
Use getOption() instead of option()
Compatibility with new stringi (#7)