Miscellaneous fixes to strings found during i18n work.

Assign valid content_type to static resource (import_static_content)

Add info about template for Checkbox problem type

Remove javascript_input and create_lti; add tools

Fix URI vendor module to be referenced via a relative URL.

Add more specific info about HTML+CSS+JS files, SOP

Django command to post submissions to ora

Don't catch all exceptions.

Modify server_track to handle being called without a request.

ORA-286

Add pagination to Studio's Files and Uploads page.

These changes are for STUD-813.

STUD-878

These changes implement STUD-813. The commit consists of the
following logical changes:
 - a REST API has been implemented for a course's assets
 - the page itself now fetches the assets client-side
 - the Backbone.Paginator library is used to support pagination
 - the AssetCollection has been refactored to extend
   Backbone.Paginator.requestPager so that it can be paged
 - an abstract PagingView class has been added to generalize
   the communication with a paging REST API
 - the AssetsView has been reimplemented to extend PagingView
 - two new child views have been added:
   - PagingHeader: the paging controls above the list of assets
   - PagingFooter: the paging controls below the assets

Add options to dump_course_structure to output inherited metadata.

LMS: Developer-centric Sass Area

Studio: Developer-centric Sass Area

* provides new .scss file for developers to add temporary/in-progress Sass for further refactor/polish
* cleans up note/import order in all application scss files

* provides new .scss file for developers to add temporary/in-progress Sass for further refactor/polish
* cleans up note/import order in shame and application Sass files

prevent failure when module does not have a data field

Very Minor tweaks to the LMS and CMS startup.

I was going to do something in the startup code, then changed my mind,
but didn't want to just discard these changes.

Fix tzAbbr() in non-English browsers #os

The function tzAbbr() causes null-reference exception when the browse returns a non-English timezone string.

add validation for grading types (allow only integers)

Hide staticpages preview on render

update rewriteStaticLinks utility function(modifiy only relative urls) +...

STUD-988

STUD-674