Preview Release v2.0.0-rc.3

Meaningful Changes

• Allow properties, behaviors, observers, hostAttributes, and listeners to be set in Polymer({}) calls
• Behaviors can only be set on the element prototype

Raw Notes

• add properties, behaviors, observers, hostAttributes, listeners on prototype (commit)

• [skip ci] update test comments (commit)

• better comment (commit)

• get behaviors only from prototypes (commit)

• behaviors ONLY on the prototype (commit)

• add instance behaviors (commit)

• [ci skip] minor doc edits. (commit)

• [ci skip] expand range of dependencies to all rcs (commit)