New needs, new regexes

Changed regex for EC numbers to account for provisional ECs

Changed ^(\d+)(\.(\d+|-)){3}$ to ^(\d+)(\.(\d+|-)){2}(\.(.*))?$, which accepts provisional EC numbers (e.g., 1.1.1.n1).

Changed regex for KEGG IDs to account for other taxonomy codes

Changed ^[A-Za-z]{3}:.+$ to ^[A-Za-z]+:.+$ to accept taxonomy codes that have less or more than three characters (e.g., pall:UYA_22060).

Also, some bug fixes

• One of the weirdest bugs ever - pandas.DataFrame.groupby has a maximum number of columns (20).
• Fix on saving box2taxon when it is empty
• Also removed some code from the time only one functional column was considered at a time