Har support - mimeType and charset

[sod]

Chrome 46, Debugger tools Har export.

I tried to repeat a request via har data.

My har file has: req.postData.mimeType === 'application/x-www-form-urlencoded; charset=UTF-8' but the switch switch (data.postData.mimeType) { in https://github.com/request/request/blob/master/lib/har.js#L63 does not expect to have the ; charset=UTF-8 in here.

The request itself works. But if I modify the postData, it is not recognised as no switch/case matches.

[simov]

@sod check out this PR #1876