Make library compatible with workers
Make library compatible with workers

Pulled from 4.x branch, see #1894.

handlebars-lang/handlebars.js,mosoft521/handlebars.js,mosoft521/handlebars.js,handlebars-lang/handlebars.js,mosoft521/handlebars.js,handlebars-lang/handlebars.js,handlebars-lang/handlebars.js,mosoft521/handlebars.js,handlebars-lang/handlebars.js,mosoft521/handlebars.js