[ticket/11367] Migrator throws error if migrations table does not exist

Force load_migration_state to not throw errors if the table does not exist.

PHPBB3-11367
[ticket/11367] Always freeresult

PHPBB3-11367
Merge remote-tracking branch 'EXreaction/ticket/11367' into develop

# By Nathan Guse (1) and Nathaniel Guse (1)
# Via Nathan Guse
* EXreaction/ticket/11367:
  [ticket/11367] Always freeresult
  [ticket/11367] Migrator throws error if migrations table does not exist
[ticket/11369] Reverting migration throws error

String is attempted to be unserialized

PHPBB3-11369
[ticket/11370] Effectively installed migrations not inserted into table

insert_migration() function now handles inserting/updating

Move all insert/update code to insert_migration() function to prevent this from occurring again.

PHPBB3-11370
[ticket/11363] Load module info files for extensions too

Use the acp_modules::get_module_infos function instead of our own include code

PHPBB3-11363
[ticket/11372] Migrator should only check if effectively installed if not

installed at all

PHPBB3-11372
[ticket/11363] Fix a couple bugs and throw errors if the file not found

PHPBB3-11363
Merge remote-tracking branch 'EXreaction/ticket/11369' into develop

# By Nathaniel Guse
# Via Nathaniel Guse
* EXreaction/ticket/11369:
  [ticket/11369] Reverting migration throws error
Merge remote-tracking branch 'EXreaction/ticket/11370' into develop

# By Nathaniel Guse
# Via Nathaniel Guse
* EXreaction/ticket/11370:
  [ticket/11370] Effectively installed migrations not inserted into table
Merge remote-tracking branch 'EXreaction/ticket/11372' into develop

# By Nathaniel Guse
# Via Nathaniel Guse
* EXreaction/ticket/11372:
  [ticket/11372] Migrator should only check if effectively installed if not
Merge remote-tracking branch 'EXreaction/ticket/11363' into develop

# By Nathaniel Guse
# Via Nathaniel Guse
* EXreaction/ticket/11363:
  [ticket/11363] Fix a couple bugs and throw errors if the file not found
  [ticket/11363] Load module info files for extensions too
Merge branch 'develop' into feature/revisions

# By Nathaniel Guse (6) and Nathan Guse (1)
# Via David King (5) and Nathaniel Guse (1)
* develop:
  [ticket/11363] Fix a couple bugs and throw errors if the file not found
  [ticket/11372] Migrator should only check if effectively installed if not
  [ticket/11363] Load module info files for extensions too
  [ticket/11370] Effectively installed migrations not inserted into table
  [ticket/11369] Reverting migration throws error
  [ticket/11367] Always freeresult
  [ticket/11367] Migrator throws error if migrations table does not exist