- @version in file header level isn't used on code docs, it is intended
for API versions at class or method level
- avoids needing to update all these files on version increment
- avoids needing to regenerate SRI hashes for privatebin.js through
extra phpunit run
- simplifies VERSION_FILES list
- avoids having to filter above list during loop
- adds a few missing doc bloc headers
having had to re-do all of these steps on a new environment, I noticed
some inconsistencies and updated the doc:
- moved unit testing doc into common doc folder, so it is easier to find
- removed no longer supported Janitor reference
- removed note regarding generated test duration, current version takes
less than a minute
- addressed each function removal & phpunit deprecations
