Bumping version and shrinkwrap, updating changelog

Bumping shrinkwrap to 1.3.15

Updating changelog, bumping version to 1.3.10

Putting version on changelog

Locking gulp at 3.8.8 so it doesnt introduce v8flags dependency thats…

… causing crash. Bumping to 1.2.13

Adding documenation to README about working around proxies, as well a…

…s adding in the additional http_proxy in lib/ionic.js