Merge pull request #3 from aolley/master

Change to use print_error instead of deprecated error function
Initialise PHP object before assign properties
Refs #7070: Drag & drop into moodle course

Files will be intecepted by EQUELLA
Refs #7070: Added option to turn off file inteception
Refs #7070: Instantly upload files to EQUELLA
Refs #7070: Removed dnd hook, fixed function call
Refs #7070: Option to enable DnD hook
Issue #4: Use new window option when create new EQUELLA instance
Refs #7070: Improved admin settings
Refs #7070: Improved activity settings
Refs #7070: Improved exception message
Refs #7070: Change help text
Refs #7070 Tweak admin settings
Improved option texts
Error checking rest api response
Refs #7465 Fixed larger image viewer display in moodle
Fixed setting options
Refs #4 added a global new window/same window setting
Make equella_intercept_files option visible
Refs #7591, fixed shared secret label