Remove aural CSS numerial styles from CSSProperties

Those styles are not implemented in known browsers.
Updates to perf

ReactDefaultPerf:

* Show times as float instead of string. This means they're sortable.
* Add count columns to all types and average to exclusive time.
* Include mountComponent where updateComponent time is measured.
* Increment count on _renderValidatedComponent instead of update.

ReactDefaultPerfAnalysis:

* Return counts with all summaries.
un-revert textContent, support multi-line strings in modern browsers

reverts 23ab30ff873fba816129cafa0c40112dd2ee990d because the issue it fixed doesn't seem to be a problem
anymore. textContent should be better for more things anyway, as the
original 309a88bcf62c1c64a2b91c0eb753c19209a425b2 indicates. It should be faster because innerText
requires layout.

This also allows us to use strings with newlines in our rendered output
and have confidence that they will render the same on subsequent
re-renders. This is especially useful for es6-style backtick multi-line
strings. This will be more consistent as textContent is supported almost
everwhere so we won't have differing behavior between webkit and
firefox.

see https://github.com/facebook/react/issues/1080