IE8 improvements for docs site
Add note on browser support to docs
Merge pull request #141 from react-bootstrap/ie8-docs

IE8 improvements for docs site
Merge pull request #144 from react-bootstrap/browser-support

Add note on browser support to docs
Docs tweaks to IE8
Fix bad `PropType`s in `PanelGroup`
Bump package version number to 0.11.0 on master