re-check browser support if user_agent changes, fixes CNVS-5025

previously we stored whether your browser is supported in the session
(so as not to add extra overhead to every request). we still do that, but
now we re-check whenever the user_agent string changes

test plan:
1. install an older chrome or firefox
2. log in to canvas
3. see the orange bar
4. upgrade your browser
5. you should not see the orange bar in canvas
6. additionally, if you change your user_agent string on the fly, the
   orange bar should show or not show accordingly when you refresh

Change-Id: I5c21c3c7adf30d4dd5b90189c3d9b3a33f8fa33f
Reviewed-on: https://gerrit.instructure.com/19189
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Stanley Stuart <stanley@instructure.com>
QA-Review: Cam Theriault <cam@instructure.com>
Product-Review: Bryan Madsen <bryan@instructure.com>
fix margin on "please log in" warning message

fixes CNVS-5039

test plan: go to any page that needs auth such as /courses/X when not
logged in. the "please log in" header shouldn't overlap with the "you
need to be logged in..." message.

Change-Id: Ide1b239a14ee8aa58608055097d88487b65e00ba
Reviewed-on: https://gerrit.instructure.com/19211
Reviewed-by: Cody Cutrer <cody@instructure.com>
QA-Review: Clare Hetherington <clare@instructure.com>
Tested-by: Jenkins <jenkins@instructure.com>
Product-Review: Brian Palmer <brianp@instructure.com>
work around a lockdown browser rendering issue

lockdown browser has an issue when the base explorer install is IE9 where the
first page rendered after a popup window is opened does not render correctly.
since it only happens in the first page after the popup is created, we are
working around it for now by loading a dummy page as the first page which
automatically redirects to the actual quiz page.

fixes CNVS-3881
refs CNVS-4853

test plan
- make sure taking quizzes works fine with LDB
- in a system with LDB and a base IE9 installed
- start taking a quiz, it should render correctly
- try with/without oqaat, and other quiz options

Change-Id: I5bf51cce9d7722e62941dd8db0d40163ccc032bd
Reviewed-on: https://gerrit.instructure.com/19272
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Stanley Stuart <stanley@instructure.com>
Reviewed-by: Brian Palmer <brianp@instructure.com>
QA-Review: Amber Taniuchi <amber@instructure.com>
Product-Review: Bryan Madsen <bryan@instructure.com>
bootstrap: make 'flag quiz question' button visible

fixes CNVS-5028

test plan:
- Edit a Quiz and create a new Matching question. Make sure students
  can see the correct answers by enabling that option in the quiz.
- Resize the window, horizontally, as small as you can
- Ensure that the text fields don't appear as scrollable
  horizontally
- start taking a quiz. make sure you get at least one question wrong.
- the button to flag questions should be available
- after you take the quiz, make sure the red/green/arrows that show up
  for the submission on results on the left look fine.

Change-Id: I9367ef6ab5b40d48d9d640a3c8f4c0c7c628e12d
Reviewed-on: https://gerrit.instructure.com/19191
Tested-by: Jenkins <jenkins@instructure.com>
QA-Review: Myller de Araujo <myller@instructure.com>
Product-Review: Stanley Stuart <stanley@instructure.com>
Reviewed-by: Cameron Matheson <cameron@instructure.com>
show student progression on module page for large_roster

The module progressions for individual users were removed
for courses with large_roster set. Only the teacher's call
that loads all the progressions for the whole class should
be blocked while still allowing individual's info to load.

Test Plan:
 * on a course with large roster set:
 * create a module with a completion requirement
 * when a student fulfills that requirement, the module page
   should show the green checkmark indicating it is done

closes 	CNVS-5055

Change-Id: Id493459a77c32a7d2a99b19376a822f058896912
Reviewed-on: https://gerrit.instructure.com/19319
Tested-by: Jenkins <jenkins@instructure.com>
QA-Review: Adam Phillipps <adam@instructure.com>
Reviewed-by: James Williams  <jamesw@instructure.com>
Product-Review: Bracken Mosbacker <bracken@instructure.com>

Conflicts:
	app/controllers/context_modules_controller.rb
text field being too long when inserting wiki page into discussion

fixes CNVS-5060

test steps:
1. Go to the add new discussions form page
2. On the right side, click the 'wiki pages' dropdown
3. Click 'Link to a New Page'
4. Ensure that the text field and form appear good

Change-Id: I7761283add7c580b8ea443a95aaf0c09833826df
Reviewed-on: https://gerrit.instructure.com/19318
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Zach Pendleton <zachp@instructure.com>
QA-Review: Cam Theriault <cam@instructure.com>
Product-Review: Eric Berry <ericb@instructure.com>
resolved spacing on edit lti form. fixes CNVS-5027

test steps:

- go to a course and click settings
- click the external tools tab
- edit or create an existing tool by URL
- the text underneath the "Shared Secret" box should be spaced
  correctly

Change-Id: I4ae38a5306975d9d9dac25aa6af5170063422e79
Reviewed-on: https://gerrit.instructure.com/19314
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Zach Pendleton <zachp@instructure.com>
QA-Review: Adam Phillipps <adam@instructure.com>
Product-Review: Eric Berry <ericb@instructure.com>
add vertical scrollbar to scheduler appointments.

fixes CNVS-5037

when viewing a scheduler appointment detail popup as a
student, some content would not be visible if the
appointment had a description and > 5 students. now the
content inside of the popup scrolls vertically.

test plan:
  * as a teacher, create an appointment group with the
    'allow students to see who has signed up for time
    slots' option selected and a description > 5 lines;
  * as five different students in the course, sign up for
    the appointment group;
  * as one of those students student, click the appointment
    group in the scheduler week view to open the details
    popup;
  * verify that the details popup content is scrollable and
    is all visible.

Change-Id: I32d7584b11e76f76fb7ed5e8345fee9121e675ad
Reviewed-on: https://gerrit.instructure.com/19275
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Jon Willesen <jonw@instructure.com>
QA-Review: Clare Hetherington <clare@instructure.com>
Product-Review: Zach Pendleton <zachp@instructure.com>
remove border on user-content iframes

fixes CNVS-5026

test plan:
 - put an iframe in a wiki page
 - it should view without the sunken border

Change-Id: I463392be59d32a7f5c861dcef6797c6ea430e1ed
Reviewed-on: https://gerrit.instructure.com/19276
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Ryan Florence <ryanf@instructure.com>
QA-Review: Adam Phillipps <adam@instructure.com>
Product-Review: Jeremy Stanley <jeremy@instructure.com>
treesame commit of origin/stable/2013-03-30

Treesame-Commit-Id: 1605aafb8693cd1415f51b97bd2fec6d3656e79c