Add passing offsets over plotpan event

Unified this behavior with plotzoom event as in pull #34 flot/flot@1b6c4e933ade3f03d634dfaa6357e82beda3bc55

Use bind, rather than .mouseleave, because we officially still support
jQuery 1.2.6, which doesn't define a shortcut for mouseenter or
mouseleave.  This was a bug/oversight that was fixed somewhere around
1.3.x.  We can return to using .mouseleave when we drop support for
1.2.6.

Change evaluation order for calculating percentage.

Rounding errors are introduced when calculating the percentage when the total is 100 (for example if percentages have already been calculated). Calculating (total/100) first eliminates the error in this case.

When the placeholder has (or inherits) the HTML 'dir' attribute or CSS
'direction' we get unexpected results from text metrics, resulting in
visual glitches on the axes.

The suggested solution in #716 was to set ltr on the placeholder, but
this introduces its own problems, since the user probably *does* expect
rtl on items like the legend.  So we'll instead set ltr only on the
canvases.

We should review this behavior at some point; rtl is something we need
to handle, not work around.  It also needs to be kept in mind as we move
canvas-text into a plugin.  But for now this solution at least ensures
consistent behavior.

As pointed out in a comment to #832, initializing maxIndex to zero
results in the creation of a single color even when all indexes are
fixed.

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.