Add article licensing, update names to 3.1.2 schema

[ctgraham]

• Add article license metadata (url, copyright holder, copyright year)
• Update names to 3.1.2 schema (givenname, familyname)
• minor bugfixes (discipline element, escaping section abbreviations)
• documentation updates (gitignore, README, files)

[ajnyga]

Thanks! There's actually story behind the misspelled discipline tag https://github.com/pkp/pkp-lib/issues/3357