fix(select): multi-select checkmark icon displays correctly without additional CSS

Reverts commit d167af80b5e055d8195559975216a1fde353230f and instead moves the checkmark icon element to before the label span. As the checkmark icon is "pull-right", it can be placed before the label.
fix(tabs): add `track by $index` to the base template (fixes #1201)
test(tabs): add two simple test cases to check for `track by $index` on the tabs template
test(tabs): create a new set of tests for checking the functionality of nested tabs
fix($animate): update animate.enter() so new dom objects are inserted in the same place they were w/angular 1.2
this is due to changes from: https://github.com/angular/angular.js/commit/1cb8584e8490ecdb1b410a8846c4478c6c2c0e53

Conflicts:
	src/tooltip/tooltip.js
fix(typeahead): fix selected object display
chore(karma): switch ie remote testing to quieter platforms
chore(npm): update devDeps
chore(karma): tweak timeout configuration
test(datepicker): add test to check days order in datepicker

Added a new gulp task called 'test:timezone' that sets the environment timezone for PhantomJS to use. It expects a parameter on the command line with the name of the timezone to use, like: 'gulp test:timezone --America/Sao_Paulo'.
Using this new task, the new test that checks for days order in datepicker fails for America/Sao_Paulo because of changes in Daylight Saving Time - from what I could understand, Brazil changes the time at midnight and the datepicker uses dates with time set to midnight, so when it increments one day, it goes back to the previous day, which caused repeated days to show up on the calendar.
fix(datepicker): fix duplicate days in picker when DST changes

Depending on the browser timezone, the datepicker might show duplicate days when the DST causes hours to go back - this will happen in São Paulo, Brazil timezone in 18th October 2014 at midnight, when the time will go back 1 hour, so the datepicker will show two 18th days and miss the 19th, as shown in #1133.

If DST causes time to go forward, there is no problem because the day will still be incremented. If time goes back, the fix checks if hours are > 12, meaning we went back to original day, and add +2 hours to compensate for the hours going back, causing the day to increment as intended. (Code copied from jquery ui)
fix(tooltip): fix undefined element when triggering multiple times in fast sequence

Clicking multiple times fast on the dropdown button in docs was causing an exception because the element references were being cleaned up in 'hide' animation callback. When the show/hide calls were executed in specific timming, the 'hide' callback was being run after calling 'show' which caused the $isShown flag to be true but the element to be destroyed.

By calling 'destroyTipElement' only in 'show' before creating a new one, we avoid this issue with no noticable impact on allocated resources.