Fixes #471. This prevents transition.remove() from clobbering another transition
"end" event listener, or vice versa.

See #136.

Fixes #446.

There's an edge condition which is not discussed in the original algorithm
("Visualization of Large Hierarchical Data by Circle Packing", Wang et. al):
what happens if the first intersecting circle C_j is equidistant from C_m and
C_n? In other words, it is both after C_n on the front-chain, and before C_m.
The correct answer is that you should splice the smaller of the two circles. If
C_m is smaller than C_n, then splice from C_j to C_n and set C_m to C_j;
otherwise, splice from C_m to C_j, and set C_n to C_j.

Simplification to spline example.

The tick sizes need to be set, else they grow from zero.

A small optimisation: only call insertBefore() if node.nextSibling isn't
already what we want, so that document nodes that are already in the
correct order can be skipped.

Fixes #395.

Fixes #412.

Also, set vows version to "0.6.x" as the exact patch version is not
important right now.

corrected fix for the calendar example: do NOT mix UTC and Local TimeZone date operations in calculations which depend on identifying day/month transitions - default JavaScript Date object works with 'local timezone'. Fix tested in AZ/USA and Amsterdam/EUR timezones.

the use of getUTCxxx() instead of getXxx() draw the wrong path for some timezone, the t1 will be previous year instead since t0 is not UTC timezoned

bugfix for D3.JS bug in calendar demo: edge around months was drawn incorrectly; this was apparent at each December month.

Array.reverse does not create a copy of the array, so we must slice first.

Thanks to "code golfer" @mbostock. :)