improved README English. added links, use-cases

I'm not sure if possessive `canvas` is `canvas'` or `canvas's`?
Merge pull request #8 from tomByrer/patch-1

improved README English. added links, use-cases
Exposed webworker, closes #11
readme update
Moved blur to separate file & added benchmark
opt: unified convolvers code, moved alpha-channel fix to external fn
Updated benchmark
Browser files rebuild
1.0.5 released