Merge pull request #17 from aolley/master

callbackmulti: The section passed to course_add_cm_to_section is the relative section number
Refs #17 section id fix
EQ-520 Fixed grade scale
Hide LTI outcome callback url
Refs EQ-541 Add LTI "launch_presentation_document_target" parameter
EQ-545 Default window size is configurable

1. Increase default window width
2. Window size is configurable
3. Append resizable=1 to existing popup option
Refs EQ-559 boolean param should be string
Refs EQ563

1. Add [x] button in dialog
2. Use iframe instead of <object>
don't escape popup url
Added filesize to curl put method
Assign course id to $equella
Enable LTI option should be off by default
Added options desctiptions
EQ-659 cached mod info should use popup.php
Version shouldn't be empty
EQ-671 Dont sign request if key and secret are empty
Close ltireturn window
Don't try to modify modinfo
EQ-703 Use equella's curl library
Refs EQ-730 Store equella resource mimetype in db