Update jquery.flot.threshold.js

Handle undefined axisOptions in 0.9-work

Convert all tabs to 4-space indents.

Displays the serie base color and the threshold color side by side in the legend.
When no treshold is color is set, default black color is used.

0.9 jshint indent4

- Doesn't differentiate between tabs and spaces
- Switch/Case indenting may seem odd to some

0.9 grunt build

0.9 add editorconfig

Allows for consistent spacing and indenting when combined with supported
IDEs

I ran into this issue when upgrading from 0.8.1 to 0.9-work.

Added axis labels and rotated text support.

The labels are rotated counter-clockwise for left axes and clockwise for
right axes.

Labels are provided via a 'label' option on the axis, and can be styled
with the flot-axis-label class.  The labelFont option works similarly to
tickFont, as an override for the default font or the flot-axis-label
class.  The labelPadding option adds extra space between the axis and
its label.

Since most plots with axis labels currently use @markrcote's
flot-axislabels plugin, we also support the axisLabel and
axisLabelPadding options, and the axisLabels / axis[name]Label CSS
classes, to make it as easy as possible to transition from that plugin.
These are deprecated, and will be removed in 1.0.

The implementation uses the internal text API introduced in 0.8.

Updated the axis option defaults and docs for tickColor, tickFont,
tickWidth, and tickHeight. Also re-organized the API docs to match the
master list, and revised many areas for clarity.

Conflicts:
	jquery.flot.js
	jquery.flot.threshold.js

We can inline the dependencies automatically as part of the build
process.

Add table of contents

The reference document is quite large; a table of contents would help readers navigate and find topics. (TOC was generated via [DocToc](http://doctoc.herokuapp.com/))

It's a little confusing, JSHint complains, and it doesn't make a big
difference anyway.

Updated threshold plugin to work with 'above' operator. Resolves #1059.

We trust that jquery.flot.time.js checks for timezoneJS's existence
before using it.