simplify unary negation operator
add benchmarking task
Merge pull request #24 from meganemura/add-benchmarking-task

Add benchmarking task
Merge pull request #25 from meganemura/simplify-unary-negation-operator

Simplify unary negation operator
Asset interface: removed #path=, #to_n
Web::Asset matches updated Asset interface
Sound interface: removed #pause
Web::Sound matches updated Sound interface
Web::Sound based on Web Audio API (resolves #10)
fixed Web::Sound fatal error if playing before loading
Merge branch 'sound'