Modifying the numericTicks algorithm to include the last 'nice' tick
(either at range end or just past it).

This has the effect of making a (grid lines, axis label) pair always
show up together or not at all. Previously it was possible to get a
label but no gridline at the edge of the chart.

Squashed commit of the following:

commit 32955f836c3c32c11f009ae250cd35682d641e5c
Merge: d3b7c40 0b99641
Author: Dan Vanderkam <danvdk@gmail.com>
Date:   Mon Sep 16 17:18:40 2013 -0400

    Merge branch 'master' of https://github.com/blindmonkey/dygraphs into 269-end-ticks

commit 0b996410efcb7a53315347c8cea38dc225f069ee
Author: Sergey <grabkovsky.s@gmail.com>
Date:   Mon Sep 16 17:08:36 2013 -0400

    Reverting multi-csv

commit 3f72c23c3ebc23adc64dd2605175ff163491d8e2
Author: Sergey <grabkovsky.s@gmail.com>
Date:   Mon Sep 16 17:07:26 2013 -0400

    Changing it so that the right-most X axis tick isn't displayed, and changing the tests to reflect that

commit 3605ec18fb45718dca3dbd3bfb818adb5acc79eb
Author: Sergey <grabkovsky.s@gmail.com>
Date:   Mon Sep 16 16:40:18 2013 -0400

    Reverting whitespace stuff

commit 11959a26e45be3481425f3ba68d78e63730eab4a
Author: Sergey <grabkovsky.s@gmail.com>
Date:   Mon Sep 16 14:43:41 2013 -0400

    Reverting multiple axes old test

commit 4d91af0850a1fa72f693c497ac62e88e35c505eb
Author: Sergey <grabkovsky.s@gmail.com>
Date:   Mon Sep 16 14:42:56 2013 -0400

    Reverting multiple axes test

commit 40b6ea279591df646f10d3ec44f760a20b42cf8a
Author: Sergey <grabkovsky.s@gmail.com>
Date:   Fri Sep 13 14:14:29 2013 -0400

    Changing layout to not layout ticks whose gridline is slightly offscreen.

commit cec9c2857c3c03b14521ccfb4a44bbb4d7163776
Author: Sergey <grabkovsky.s@gmail.com>
Date:   Thu Sep 12 13:26:12 2013 -0400

    Adding tests for the numeric ticker algorithm change.

commit 106c0318cdf6c763a06545cf25f6ef66084cadf7
Author: Sergey <grabkovsky.s@gmail.com>
Date:   Thu Sep 12 12:16:35 2013 -0400

    Changing numericTicks so that it returns the last nice value that might be just outside the axis