Make scanning for meta encoding much quicker
Make scanning for meta encoding much quicker

Previously, this code tried to match everything with strings
beginning with "<"; now we jump forward to each "<" and compare
there. This also alters the jumpTo implementation to avoid
computing a (perhaps long) slice, making repeated calls O(n^2).

html5lib/html5lib-python,html5lib/html5lib-python,html5lib/html5lib-python