* Migrated several additional tests to use new .toWarnDev() matcher
* Migrated ReactDOMComponent-test to use .toWarnDev() matcher
Note this test previous had some hacky logic to verify errors were reported against unique line numbers. Since the new matcher doesn't suppor this, I replaced this check with an equivalent (I think) comparison of unique DOM elements (eg div -> span)
* Updated several additional tests to use the new .toWarnDev() matcher
* Updated many more tests to use .toWarnDev()
* Updated several additional tests to use .toWarnDev() matcher
* Updated ReactElementValidator to distinguish between Array and Object in its warning. Also updated its test to use .toWarnDev() matcher.
* Updated a couple of additional tests
* Removed unused normalizeCodeLocInfo() methods