Fix incorrect display of NaN with the default tickFormatter.

Change-Id: If53fdb1bf9563834c58cf2b569d0e1a6a7155eb8

Revamped the built-in examples.

Give any direct child of demo-containre the same style, so it can be
used for both #placeholder and #overview.

Added explicit border-spacing to compensate for global removal of
padding.  Flot should really take care of this itself; layout-critical
styles shouldn't depend on the user-agent defaults.

Slightly widened the page to account for the fact that most people have
widescreen monitors these days.  Also made text larger and more legible,
and created a nice 'clipping' effect for the placeholder.

flot.threshold: insert generated series after original, not in the end

To improve organization with the increasing number of examples, every
example page is now the index of its own subdirectory, which contains
all the files specific to that example.

Thus, prevent it from becoming topmost (it may cause strange looks if
original series is not topmost: some part of it becomes topmost and
overwrites some lines and points that should be above it instead).

Fix an error in plot offset calculation.

Correction calculation error margin 

Ensure that tickSize updates on subsequent calls to setupGrid.

Fixed jQuery version dependency (we require 1.2.6, not 1.3.2) and
whitespace.

Flot's semver is 0.8.0-alpha, and it (for now) requires jQuery 1.2.6,
not 1.3.2.

Adding component.json for bower.

Added a series 'zero' option to control automatic scaling.

Adapted from pull request #17.

Always draw crosshair on half-pixels to prevent aliasing.

Add passing offsets over plotpan event

Due to limitations in our plugin architecture, the categories plugin
duplicates code from Flot's core for adding a dummy point to snap the y
axis to zero.  We can get rid of this duplication in 0.9; for now we'll
just update the duplicate to match the change in core that introduced
the new 'zero' option.