Remove 'Return to Today' button/link

There is concern for how much event content is visible at mobile widths. This link is redundant (there are 2 other ways to access today's events—the date on the calendar widget and the above 'Day'/'Today' link) and it pushes content further down the screen.

I think in future sprints we should look at ways to incorporate this link's AJAX into other areas of Events.
Merge pull request #111 from unl/kabel-four

Use the hosted version of the framework scripts and styles
Merge pull request #109 from skoolbus39/rdee-four

Remove 'Return to Today' button/link
Use the standard way of accessing the grandparent

The non-standard (easier to read) `$this->getInnerIterator()->current` does not seem to work in php 5.3
Don't reuse the DatePeriod object

php 5.3 does not automatically rewind the DatePeriod object, which can cause hard to debug errors.
Merge pull request #112 from mfairchild365/DatePeriod

Better support for 5.3
Add custom iterator class for returning Day objects from DatePeriod
Use IteratorAggregate to work around DatePeriod rewind issues

Each iteration will return a new iterator with a fresh DatePeriod
Use the IteratorAggregate pattern in Week view too