Don't add an empty ext_manager
Only save/resync if we actually made a change to ext_cachemanager
Update HTML code in File Manager

Tidy up the HTML code in File Manager, update the DOCTYPE to the correct
definition, update the SCRIPT tags and misc. small updates.
Merge pull request #378 from ExolonDX/master

Update HTML code in File Manager
Close the BR tag correctly

Close the BR tag correctly according to W3C standards, this reduces the
errors in "pkg_mgr.php" and "pkg_mgr_installed.php"
Merge pull request #379 from ExolonDX/master

Close the BR tag correctly
Write this during every sync to make sure it's present and not missed
bump