Security update

Addresses same issues present in 7.x-1.x in terms of security: https://www.drupal.org/sa-contrib-2019-009

And:

• Issue #2962423 by weseze: Why is it necessary to flush the cache after amending the permission of a node for changes in the access restriction(s) to take effect?
• Re-factor SQL queries to use class abstraction as opposed to procedural calls.

Corrected issues surrounding security advisory SA-CONTRIB-2019-009 (https://www.drupal.org/sa-contrib-2019-009)
Addressed compatibility issues with SQL queries regarding PostgreSQL
Rebuilding of node permissions required after update.

Fixes SA-CONTRIB-2019-014

Fixes SA-CONTRIB-2019-014

Resolves Anti Spam by CleanTalk - Critical - Cross site scripting and SQL Injection - SA-CONTRIB-2019-010.

Bug fixes and other minor improvements

Revise generated links to use a fileid instead of embedding the url directly.

Fixes Public Download Count - Less critical - Open Redirect Vulnerability - SA-CONTRIB-2019-012.