Bug #1019896 - explicitly setting accept headers for FF.

FF was replacing headers instead of appending them so this commit
explicitly includes 'text/plain' and '*/*' in order to fix the
org switcher.  Also includes a padding fix for the org switcher
in FF.
Merge pull request #3193 from waldenraines/bug-1019896

Bug #1019896 - explicitly setting accept headers for FF.