Allow the pie chart to redraw on resize or update.

When a pie's labels don't fit within its container, the pie is redrawn
with a smaller radius until the labels fit, or a fixed number of retry
attempts are exhausted. The redraw flag was not reset on success,
however, which prevented the pie from being redrawn again after a resize
or update.

Previously the container dimensions were checked only once, which
prevented the pie from changing in size as its container was resized.

Eliminate uses of $.browser, since it is no longer present in jQuery 1.9, and some of the cases were no longer necessary anyway.

Document the affected versions of opera, and replace $.browser.opera with a line to detect only affected versions

Remove Internet Explorer specific code, that appears to have no impact on actual rendering see bug #905

This addresses #906, the case where a fixed color index on a series
results in the color generator producing one color less than is actually
needed.

Add nonstandard %q datetime specifier for quarters.

Issue: #890: Fix broken behavior for interacting demo

Removed unnecessary canvas skipPositioning flag.

The primary canvas uses position: absolute while the overlay canvas does
not.  This can cause the two to get out of alignment in rare cases when
floating elements are placed near the plot placeholder.  There doesn't
appear to be any reason why the overlay can't also be
absolutely-positioned, so I've just removed the flag entirely.

Also fixed formatting and removed unused change to tickFormatter args.

Updated license headers for #805.

Added licensing information to each file's headers, along with some
minor cleanup.

Update timezone-js and Olson db; list sources in README.md.

Fixed global variables and missing seimcolons.