Don't blindly trust toUnicode when building toFontChar for non-standard fonts without a font file (issue 4934)
Add pdfBugEnabled to the default preferences
Disable the developer hash parameters by default in PRODUCTION builds of PDF.js
Additional heuristics to recognize unknown glyphs for toUnicode (bug 1027533)
Fix code style issues in pdf_find_controller.js and build strings more efficiently
Implement text normalization for page content and queries
Use null instead of [] for ops with no args.

This reduces peak RSS on one test file from ~600 to ~560 MiB.
Refactoring text layer builder
Convert the text layer builder to a class
Refactoring PDFFindController in the text layer builder
Merge pull request #4987 from timvandermeij/text-search-refactoring

Refactoring PDF find controller and implementing page content and query normalization
Merge pull request #4982 from nnethercote/use-null-for-zero-args

Use null instead of [] for ops with no args.
Removing unnecessary includes from text selection example
Merge pull request #4991 from timvandermeij/text-layer-builder-refactoring

Refactoring text layer builder and converting text layer builder to a class
Restructured EvaluatorPreprocessor_read to be more natural.
Merge pull request #4944 from Snuffleupagus/issue-4934

Don't blindly trust toUnicode when building toFontChar for non-standard fonts without a font file (issue 4934)
Merge pull request #4976 from CodingFabian/restructure-evaluator-read

Restructured EvaluatorPreprocessor_read to be more natural.
Merge pull request #4980 from Snuffleupagus/bug-1027533

Additional heuristics to recognize unknown glyphs for toUnicode (bug 1027533)
Zero the height and width of the WebGL canvases on cleanup
Combine re element into constructPath