Disable IE Compatibility Mode in docs, examples

[juthilo]

Fixes #10788

Should there be explanatory comments above the new tag?
Did I miss anything?

/to @cvrebert @mdo

[cvrebert]

LGTM.

[FagnerMartinsBrack]

FWIW, It is wise to use that IE crap in the http headers when possible to avoid some edge case stuff, more details.

[mdo]

Until tests pass, we'll have to wait on this (I rather dislike those emails :p).

Also, we should mention in the http://getbootstrap.com/getting-started/#browsers docs that we include this in the docs.

[juthilo]

@mdo: @cvrebert said that validation issues don't cause our Travis builds to fail - is that not correct? Both builds I started failed because of that timeout problem at browserstack, AFAICT.

[juthilo]

I added a note about our use of this tag as requested. Newest Travis build passed (even though it exited with 1, which seems very strange to me...). All good?

[juthilo]

Ah, Travis was just showing the old log to me. So, validation errors definitely don't cause the tests to fail and merging this in shouldn't cause more notification emails for you, @mdo. :) 💃