Separate wrapper classes in corelib
Move math and encoding to stdlib
Cleanup some #{self} => self references in string/module
Some cleanup in regexp
Cleanup template
Whitespace
Fix some Date methods
Add custom specs for Date (for missing rubyspec tests)
Fix Date.parse() for simple iso8601 date strings
Rename the String and Array inheritance files for cherry-picking clarity
Typo
Fix path in example Gemfile
Use Rack::Deflater in Opal::Server

Makes running specs remotely a lot faster when your final output is 2M
of compiled JavaScript.

Also backwards compatible since it doesn't compress unless it's asked
to.
Add Native::Object#merge!
Use hasOwnProperty.call instead of calling the method

In IE8 and below calling `hasOwnProperty` on a DOM element or anything
else it doesn't like will blow up, but using `.call` fixes this.
Fix Regexp.escape to escape \t, \r, \n, \f characters
Add Regexp.quote as an alias of Regexp.escape
Cleanup Regexp.escape
Kernel#is_a? should check against included modules as well
Also catch Errno::EPIPE in uglify and gzip