Refactors SVG api
Adds svg.js to the generic and singlefile builds
Fixes image and font embedding
Merge pull request #5188 from yurydelendik/svg-refact

Refactors some SVG api and includes svg.js in the build
Use cff glyph width in the hmtx table
Merge pull request #5184 from yurydelendik/cff-width

Use cff glyph width in the hmtx table