Some IE(7) fixes

[willembult]

Links without href attributes navigate off-page in IE<=7. Also, indexOf is not supported on arrays, and offsetWidth is not writeable.

[pkozlowski-opensource]

@willembult Thnx for the interest in the project and this pull request but unfortunately it can't be merged as-is. There are several reasons for this:

• your change introduces dependency on jQuery and this project doesn't have this dependency and we don't want to introduce it
• we are advising people to use a polyfil for missing JavaScript APIs. Currently our favorite is https://github.com/kriskowal/es5-shim You can see it in action here: https://github.com/redaemn/bootstrap/blob/3ecfebf9f029af22fcb018b49275a2bafd7623b8/misc/demo/index.html

As a more general remark I'm not sure we can afford supporting IE7... It comes down to time spent vs. benefit. It is voluntary run project and we got only limited amount of time available... At the moment we are trying to add IE8 support through #249

Going to close this one for now as we can't merge it as-is. But if you are willing to help us with IE7 support a new pull request would be awesome, taking into account constraints of this project.