FS#2415 add  to mediamanager (refactor pageinfo() and shift MEDIAMANAGER_STARTED after mediainfo() sets up )
fix missing 'subscribed' key
some unit test, more required
another test todo
Merge branch 'master' into FS#2415
refactor info functions test

pageinfo() test no longer required, unit test committed elsewhere and
verified against both previous and updated versions of pageinfo() fn.

basicinfo() and mediainfo() tests separated each into their own test
file.
(incl. the refactored file)
make  global, ensure  created in mediamanager is global and merged with any pre-existing
include image info in  in detail.php; ensure  populated before DETAIL_STARTED event
fix comment grammar
Added comment to DiffFormatter _escape() method

Clarify use of _escape() method in base class.
Clean internal ids in ml(), that it matches with fetch.php
The resize token was broken because fetch.php cleans the id before the token calculation, while ml() uses the raw id
Add some tests about handling of semicolons
Informative as sample implementation too
Support handle of images from ftp.
ml() can built url to these images, either fetch didn't accept them.
Update phpdocs of checkFileStatus
Added media_isexternal()
tests for media_isexternal
apply media_isexternal
Korean language update
treat empty AD credentials as NULL values FS#2781