fix passing null as Promise's onFullfilled (which is broken in Chrome 32)
Fallback to the |Dummy| Pattern when we fail to parse a Shading Pattern (issue 5509)
removed rounding of values in composeSMaskLuminosity

maskData comes out of maskCtx.getImageData, so is 0..255 clamped, and
the used multiplications will not create fractions needing rounding,
neither would addition.
increase chunk size in SMask composition to 1M pixels
Merge pull request #5516 from Snuffleupagus/issue-5509

Fallback to the |Dummy| Pattern when we fail to parse a Shading Pattern (issue 5509)
Merge pull request #5507 from palkan/fix-promise-null

Fix passing null as onFullfilled (which is broken in Chrome(-ium) 32)
Merge pull request #5523 from CodingFabian/remove-canvas-rounding-luminosity

removed rounding of values in composeSMaskLuminosity
Merge pull request #5524 from fkaelberer/increaseSMaskChunkSizeTo1M

Increases chunk size in SMask composition to 1M pixels