react 15.1.0

Ensure we're using the latest object-assign, which has protection against a non-spec-compliant native Object.assign. (@zpao in #6681)
Add a new warning to communicate that props objects passed to createElement must be plain objects. (@richardscarrott in #6134)
Fix a batching bug resulting in some lifecycle methods incorrectly being called multiple times. (@spicyj in #6650)

Fix regression in custom elements support. (@jscissr in #6570)
Stop incorrectly warning about using onScroll event handler with server rendering. (@Aweary in #6678)
Fix grammar in the controlled input warning. (@jakeboone02 in #6657)
Fix issue preventing <object> nodes from being able to read <param> nodes in IE. (@syranide in #6691)
Fix issue resulting in crash when using experimental error boundaries with server rendering. (@jimfb in #6694)
Add additional information to the controlled input warning. (@borisyankov in #6341)

Completely rewritten to collect data more accurately and to be easier to maintain. (@gaearon in #6647, #6046)

Remove some special cases for platform specific branching. (@sebmarkbage in #6660)
Remove use of merge utility. (@sebmarkbage in #6634)
Renamed some modules to better indicate usage (@javache in #6643)