Prevent rendering unnecessary pages when the HOME/END keys are pressed

Currently (at least in Firefox) when the HOME/END keys are pressed, this will trigger unnecessary rendering of pages that lay between the current page and the first/last page. Avoid this by going straight to the first/last page instead.
Add larger zoom values to zoom dropdown box
Merge pull request #4942 from Snuffleupagus/larger-zoom-values-in-scaleSelect

Add larger zoom values to zoom dropdown box
Merge pull request #4941 from Snuffleupagus/avoid-rendering-pages-when-home/end-keys

Prevent rendering unnecessary pages when the HOME/END keys are pressed
Reporting print usage
Refactor fake worker loading (issue 3862)
Renames concatenateToArray to appendToArray
Telemetry for used stream and font types
Adds telemetry to record embedding usages
Merge pull request #4952 from yurydelendik/telemetry

Collect More Telemetry Data
Uplift for B2G bug 1009780 - Improve open mechanism for downloads.
Zero the height and width of the Cached canvases before deleting.

This reduces peak RSS by about 300 MiB on my Mac when scrolling slowly through
the first 30 pages of a scanned black and white document.
faster JPEG transform
Let Parser_makeFilter return NullStream when an invalid stream is encountered (issue 3417)
Merge pull request #4955 from timvandermeij/rename-concatenate

Renames concatenateToArray to appendToArray
Merge pull request #4959 from nnethercote/zero-cache-canvases

Zero the height and width of cached canvases before deleting them.
Merge pull request #4950 from fkaelberer/fasterJPEGtransform

Faster JPEG transform
Added getOperatorList to api.js
Merge pull request #4951 from pramodhkp/getoperatorlist

Added getOperatorList to api.js
Disables broken rAF on iOS