Add in formatters.

Plottable.Util.Formatters now includes functions that generate formatters:

- identity() : String-ifies the input.
- general() : Shows at most [precision] decimal places (using round-half-up).
- fixed() : Shows exactly [precision] decimal places (IEEE 754 rounding).
- currency() : Displays fixed() values with a currency symbol (defaults to $)
- percentage() : Dipplayes fixed() values as percentages.
Actually include the source and test files.
Rename "Formatters" --> "Formatter".

Also fix breaking test due to character-encoding problems.
Fix percentage formatter to multiply by 100.
close #523
only write text to entering items
adding animator API and implementation for vertical bars.
first erase text, then rewrite
switch to preferred style of undefined check.
only pass projector through scale if it is explicitly included as 3rd argument to .project()
add auto resize listener to enqueue _invalidateLayout()
Merge pull request #536 from palantir/523-ticks

523 ticks
Convert Formatters to classes, allow Axis to take in Abstract.Formatter.

Formatters now also have an option to show only values that are unchanged by
formatting. For example:

var f = new Plottable.Util.Formatter.Fixed(3);
f.format(1); // "1.000"
f.format(1.234); // "1.234"
f.format(1.2345); // ""

This value can be set with .showOnlyUnchangedValues() and is true by default.

In addition, added in Formatter.Custom to allow the Javascript consumers of
Plottable to create new Formatters without writing TypeScript code.
Clear up odd <this> issues with Axis.
Merge branch 'master' into formatters

Conflicts:
	quicktests/gridlines-quicktest.html
disable animations during auto-resize. lots of documentation.
changing 10 msec to 15 for default anim.
make sure accessors get set even when scale is null.
use correct naming convention for animators. remove x/y accessors since they are unused. remove TODO (i didnt read the line properly)
split resize broadcaster into separate file. add accessor to resize flag. null check animator.