Don't generate bindings for all headers

[thatbakamono]

Is there an easy way to tell bindgen to not generate bindings to libc or winapi? I don't wanna do --blacklist-type and --blacklist-function like 30000 times (I can't really use --whitelist-type or --whitelist-function because there is no pattern in these names).
If not, I would propose to add something like --whitelist-header and --blacklist-header, example: --blacklist-header windows.h (It will ignore only this particular header, not all headers used by that header)

[emilio]

The problem with this is two:

• A C type can come from multiple headers, either via forward declarations, or via duplicate typedefs or signatures. So it's a bit tricky.

• Bindgen would still have to parse the whole thing anyway.

But this is not impossible, just a bit hard and with edge cases all over the place. This is in any case a dupe of #303.