Merge pull request #20 from WillemDeGroef/master

- fixed "ReferenceError: dryDesc is not defined"
added test for double-lifting pattern
extracted generic membrane implementation from revocable membrane code
added initial ideas on how to express boundaries using membranes
delete -> deleteProperty
Merge pull request #21 from angus-c/master

delete -> deleteProperty
initial implementation of Boundaries, with tests
Merge branch 'master' of github.com:tvcutsem/harmony-reflect
fixed typo
refactored getTrap helper function so it doesn't cons a bound function per trap invocation
added html test harness for testHandlers.js
fixed isPrototypeOf(arg) issue where arg is a proxy
bumped npm package no
added tests from issue #23
updated patch for isPrototypeOf
bumped nmp version no
added examples, updated spec compat section
better alignment with draft ES6 API: added ownKeys trap, deprecated 'keys','getOwnPropertyNames','seal','freeze','isSealed','isFrozen' and 'iterate' traps
added link to spec
commited test for issue #23