fix(ionInfiniteScroll): work properly if past horizontal boundaries

Fixes #1073

ion-infinite-scroll will now fire a scroll event if the user scrolls
past the left boundaries (if they exist) or the top boundaries (if they
exists).  This means infinite scroll works for vertical, horizontal, or
vertical plus horizontal scrolling situations.
fix(ionInfiniteScroll): remove listener on $destroy
chore(build): fix update-angular script
style(ionRefresher): pulling-text, refreshing-text default to '&nbsp;'

Fixes #1052.
docs(ionNavBar): chiefly recommend 'nav-title-slide-ios7' animation
fix($ionicLoading): stop race condition with show and hide

Fixes #1100.
fix($ionicPopup): stop race condition with show then hide

Addresses #1100.
refactor(ionInfiniteScroll): stop error on destroy
refactor($ionicPopup): remove test/temp code
chore(travis): distribute changelog with nightly build
chore(travis): format nightly changelog better
chore(build): remove test code
chore(travis): use github flavored markdown for nightly changelog
chore(travis): only generate nightly changelog for cur version
refactor: $animate - add $animateClassToggler to stop race conditions

Addresses #1100.

Fixes race conditions where $animate.{removeClass,hideClass} are
called simultaneously, in addition fixes any blinking that coulld be
caused by showing an element just attached to the dom.
refactor(): ggnore, ngAnimate

Addresses #1100
feat($ionicBackdrop): add backdrop show/hide service

Closes #1084
fix($ionicActionSheet): provide default functions for options

Fixes #1013
docs(ionHeadarBar,ionFooterBar): explain sub-header & sub-footer
feat($ionicScrollDelegate): add getScrollView(), getScrollPosition()

Closes #1117