Add -Format all

[sullo]

Add '-Format all' to allow saving of all (file based) report types, so a user can have them all.

Would also like to support something like '-Format xml,csv' so user can specify exactly what they want.

[sullo]

Nikto now allows multiple output files, which must be specified with a valid name and extension which matches a reporting format. For example:
./nikto.pl -h localhost -o one.sql,two.xml

The -Format option must still be used when using the shorthand '.' notation.