Added more preference variables from the available hash parameters
Removes mozResponseArrayBuffer
Disables worker if XHR does not support arraybuffer
PdfRedirector checks if plugin is still in PlayPreview mode
Merge pull request #4877 from yurydelendik/redircheck

PdfRedirector checks if plugin is still in PlayPreview mode
Version 1.0.277
Merge pull request #4879 from yurydelendik/master

Version 1.0.277
Merge pull request #4851 from orionhealth/4792-addprefhashparam

Added more preferences for the available hash parameters.
Merge pull request #4866 from yurydelendik/issue4673

Removes mozResponseArrayBuffer