Pull in patches from Zepto.js

https://github.com/madrobby/zepto/commit/6494bfa6ce4b5f152f78250bbc2daa3bed365797

https://github.com/madrobby/zepto/commit/91869d75167187c93b91e601d8ad960b26d15515

https://github.com/madrobby/zepto/commit/f750a13db58464f58308365ea1ba79ef9c71852d

https://github.com/madrobby/zepto/commit/df77bfba9cd708b7acfda48257af3368ac2f4982

https://github.com/madrobby/zepto/commit/468a99950f68b1625dad263a462b397539f7d7d2

https://github.com/madrobby/zepto/commit/ee43d3d4357365f2333dee77f1d8db16e349d9ee

https://github.com/madrobby/zepto/commit/b63783eacfe49f20b0e9169ed4597a8bf027c0ba