Fix code documentation

[frankiejol]

Review the documentation (pod) sections in the .pm files at the lib directory.

• [ ] Write documentation guidelines in devel-docs
• [ ] Check all the modules have sections: Name, Synopsis, Description, Constructors, Methods, Bugs, Authors, Copyright, License, See also
• [ ] Review methods section. Check all the methods docs are readable.
• [ ] Check all the modules show fine doing perldoc file.pm