fix: multiple events support
test: multiple events
docs: mission @function tags
test: get extension as lowercase
refactor: removed useless events
feat: file pause and resume

Solves https://github.com/23/resumable.js/issues/92
docs: changlelog updated

solves https://github.com/23/resumable.js/issues/87 and
https://github.com/23/resumable.js/issues/92
refactor: removed cancel event
feat: event afterFilesAdded added
test: test events
feat: updated node.js example
docs: updated readme file
test: travis-ci browsers added