Refactors showText: split type3, remove showSpacedText
Update web/compatibility.js

1) Remove obsolete workarounds
2) Add support comments
Fixes unhandled XObject subtype PS error
Merge pull request #4832 from yurydelendik/showtext

Refactors showText: split type3, remove showSpacedText
Merge pull request #4861 from timvandermeij/xobject

Fixes unhandled XObject subtype PS error
Adds compatibility.js to the Firefox extension
Merge pull request #4803 from mzgol/compatibility

[WIP] Update web/compatibility.js
Merge pull request #4865 from yurydelendik/issue4854

Adds compatibility.js to the Firefox extension
Reverts mozRequestAnimationFrame to compatibility.js
Added more preference variables from the available hash parameters