Fix setScale regression that affects exiting Presentation Mode on narrow window widths
Clean up test PDF references
Add verbosity as an api setting.
Set eof to true at the end of a FlateStream

At the initialization of `Lexer_getObj` (in `parser.js`), there's a loop
that skips whitespace and breaks out whenever EOF is encountered.
(https://github.com/mozilla/pdf.js/blob/88ec2bd1a/src/core/parser.js#L586-L599)

Whenever the current character is not a whitespace character,
`ch = this.nextChar();` is used to find the next character
(using `return this.currentChar = this.stream.getByte())`).

The aforementioned `getByte` method retrieves the next byte using
(https://github.com/mozilla/pdf.js/blob/88ec2bd1a/src/core/stream.js#L122-L128)

      var pos = this.pos;
      while (this.bufferLength <= pos) {
        if (this.eof)
          return -1;
        this.readBlock();
      }
      return this.buffer[this.pos++];

This piece of code relies on this.eof to detect whether the last character
has been read. When the stream is a `FlateStream`, and the end of the stream
has been reached, then **`this.eof` is not set to `true`**, because this check
is done inside a loop that does not occur when the read block size is zero:
(https://github.com/mozilla/pdf.js/blob/88ec2bd1ac/src/core/stream.js#L511-L517)

      for (var n = bufferLength; n < end; ++n) {
        if (typeof (b = bytes[bytesPos++]) == 'undefined') {
          this.eof = true;
          break;
        }
        buffer[n] = b;
      }

This commit fixes the issue by setting this.eof to true whenever the loop is not
going to run (i.e. when bufferLength === end, i.e. blockLen === 0).
Add pdf from issue 3885 to tests

Source: https://www.dropbox.com/s/ooqk82fq0gr5p6f/test-min-notext-opt.pdf
calgray: fix getRgbBuffer problem

This fixes issue 3903.
Recompressed PNG assets
Merge pull request #4045 from brendandahl/verbosity

Add verbosity as an api setting.
Adjusts heuristic for disabling Symbol encoding
Merge pull request #4001 from jryans/clean-test-pdfs

Clean up test PDF references
Only trigger warning bar on certain unsupported features.
Merge pull request #4067 from fkaelberer/PNGs_recompressed

Recompressed PNG assets
Adds glyph mapping for standard fonts
Merge pull request #4048 from brendandahl/unsupported-features

Only trigger warning bar on certain unsupported features.
Introduces LegacyPromise; polyfills DOM Promise
Update Spanish translation

Sync with latest changes and tweak a string for clarity
Merge pull request #4075 from Fitoschido/patch-1

Update Spanish translation
Merge pull request #4060 from yurydelendik/promises

Introduces LegacyPromise; polyfills DOM Promise
Avoiding double draw() calls
Merge pull request #4011 from Rob--W/issue-3885

Set eof to true at the end of a FlateStream