Implement streaming using moz-chunk-arraybuffer

Implements #4739 with `moz-chunk-arraybuffer`. Support of the http://www.w3.org/TR/streams-api/ will be easier to add.

The PDFJS.disableStream option added to disable this functionality. Currently it autodetects presence of moz-chunk-arraybuffer feature, and if enabled turns on the streaming of the PDF (in addition to range requests). The disableAutoFetch is true when streaming in process.
If range requests are disabled then `hash` won't be defined and thus throw a `TypeError` here. Let's move line https://github.com/yurydelendik/pdf.js/commit/87b1298f9663daf3e00c38e0eddf9a102ca55942#diff-985966130e4e9f07e74f562c737dee81R934 above the `if` block.

Also, this way you can move https://github.com/yurydelendik/pdf.js/commit/87b1298f9663daf3e00c38e0eddf9a102ca55942#diff-985966130e4e9f07e74f562c737dee81R938 to line https://github.com/yurydelendik/pdf.js/commit/87b1298f9663daf3e00c38e0eddf9a102ca55942#diff-985966130e4e9f07e74f562c737dee81R923 instead (saving a few ops when `disableRange === true`).