3.x Fix deps in jpa examples and do other cleanup

[barchetta]

The pokemons and jpa examples failed to run from the command line due to dependency issues. Fixed the following:

• Changed jpa and jta dependencies to compile (from provided). Added bean validation since hibernate seemed to want that
• Removed comment from init_script.sql since H2 was trying to parse the comment block as SQL. It skipped it (so test passed) but generated lots of exceptions in log
• Exclude .sql files from copyright check so we are not lured into making mistake again
• README edits
• Jakarta-fy persistence.xml

[ljnelson]

There are a few references left to 2.2; I think they need to go to 3.0.