Small fix
Reset backport
Type safe helper.isArrayLike
Polyfill
Rename webserver -> staticserver
Move declaration of jub.env
Modified trace command write to stderr
Rename commands -> tools

"commands" is ambiguous word
Add helper.readContents
Bugfix
Remove .*Buffer functions
tools.modified support multi files
Remove task validation

It is not useful
Async tasks run sequentially
run and runOnce accept callback function
Rename StaticServer
Rename watch -> Watcher
Refactoring watcher.js