Rethink how to maintain header

[fernandoandreotti]

Need automated form of maintaining header in files. This pertains authorship and license information.

Some of the things that are currently inconsistent:

• VERSION_NUMBER
• VERSION_DATE
• COPYRIGHT_YEAR
• "Last update" useless since we use git
• Website should move all to www.fecgsyn.com

[fernandoandreotti]

Maybe consider a single file with this description to reduce header verbose as well