Fix tickDecimals option broken by pull #50.

Pull request #50 inadvertently broke the behavior of axis.tickDecimals,
which previously added precision up to the given value.  The broken code
effectively ignored the setting for values with less precision.  This
fix brings back the old behavior.

It's useful to include the tickDecimals option in one of our examples,
so it's easier to test across versions.  The setting-options example is
the logical place to put it.

Tested, verified and fixed support for jQuery 1.8.

Substitute zero when .width() returns undefined, since legendWidth is
used in numeric calculations that break when it is undefined.  This
became a problem with the release of jQuery 1.8.0, which returns
undefined instead of null when an element doesn't exist.  This was fixed
in 1.8.1, but this is good practice anyway.

Use placeholder dimensions instead og canvas dimensions in calculations which fixes draw bug after introducing Retina support in Flot core

Removed implicit global variables in threshold plugin.

Cleaner and portable function to get pixelratio.

This patch is intended the make getPixelRatio function portable and cleaner :)

Previous indentation issue has also been fixed.

Thanks :)

Support different border color and widths for each side of the chart.

Edited grammatical error.

Added Szymon Barglowski, who originally reported the fmt variable.

Prevent insertSteps and fmt from becoming global.

`fmt` was being hoisted as a global variable.
Signed-off-by: Nick Campbell <nicholas.j.campbell@gmail.com>

Locally declared insertSteps by adding var s.t. it would no longer be a
global variable.
Signed-off-by: Nick Campbell <nicholas.j.campbell@gmail.com>

Added options to customize tilted pie shadows.

Fix makeCanvas for IE, broken by Retina support introduced in 179d2e1d.