support lower-case vendor prefixes in styleNames

[jbonta]

TLDR: Let's allow style={msTransform: '...', webkitTransition: '...'}

for stylenames, we recommend that JavaScript keys start with a capital letter for vendor prefixes, presumably because hyphenation is then trivial (so they start with a single leading hyphen). This forces a user to put a vendor-specific key that isn't even valid, or it produces css that doesn't really work.

We probably need to re-work this, or build awareness of vendor-specific prefixes into the core of react's style building. This comes up here too.

[IvanTorresEdge]

It would be very nice to rather have auto prefixing (and CSS hacks). You guys provide consistent DOM VM. Having a consistent CSS rules would be awesome!

[sophiebits]

I believe the vendor prefixes Webkit, Moz, ms, O are now supported consistently with that capitalization.