Adds FFC1 marker support
Subset of (pdf.js/438e3c8f6d2bd5a: Fixes for subtile bugs).
Merge pull request #16 from yurydelendik/clamp

Subset of (pdf.js/438e3c8f6d2bd5a: Fixes for subtile bugs).
Merge pull request #15 from yurydelendik/ffc1

Adds FFC1 marker support
Fixes second component in 2-component colorspace (see #17)