[ticket/9871] Update version check file to use json format

PHPBB3-9871
[ticket/9871] Use $request->variable instead of request_var

PHPBB3-9871
[ticket/9871] Restore get_remote_file

PHPBB3-9871
[ticket/9871] Restore phpbb_version_compare

PHPBB3-9871
[ticket/9871] Mark test as slow

PHPBB3-9871
[ticket/9871] Typehint and comment on var types

PHPBB3-9871
[ticket/9871] Fix tests

PHPBB3-9871
[ticket/9871] Restore get_remote_file_test

PHPBB3-9871
[ticket/9871] Allow setting the host/file to load for the version class

PHPBB3-9871
[ticket/9871] Option to force the stability when checking for updates

PHPBB3-9871
[ticket/9871] Split fast and slow version tests

PHPBB3-9871
[ticket/9871] Fix test name

PHPBB3-9871
[ticket/9871] Fix indentation on comment

PHPBB3-9871
[ticket/9871] Can set current version to use instead of the phpBB version

PHPBB3-9871
Merge remote-tracking branch 'EXreaction/ticket/9871-2' into develop

* EXreaction/ticket/9871-2:
  [ticket/9871] Can set current version to use instead of the phpBB version
  [ticket/9871] Fix indentation on comment
  [ticket/9871] Fix test name
  [ticket/9871] Split fast and slow version tests
  [ticket/9871] Option to force the stability when checking for updates
  [ticket/9871] Allow setting the host/file to load for the version class
  [ticket/9871] Restore get_remote_file_test
  [ticket/9871] Fix tests
  [ticket/9871] Typehint and comment on var types
  [ticket/9871] Mark test as slow
  [ticket/9871] Restore phpbb_version_compare
  [ticket/9871] Restore get_remote_file
  [ticket/9871] Use $request->variable instead of request_var
  [ticket/9871] Update version check file to use json format