Fix for mountain chart with preceding 0 value.

Rookie mistake.

Update teh spec files with a test for this.
Hide tracker if content null or undefined.

For #207.  If the user returns an empty string, I won't decide not to
show it.
Fixed image blurring

When position becomes a float the image is blurred. By using parseInt we force it to render properly and might even improve performance according to the article.

See http://www.html5rocks.com/en/tutorials/canvas/performance/#toc-avoid-float
Added radix to prevent issues with parseInt
Merge pull request #217 from splitfeed/patch-1

Fixed image blurring of markers
Add build without 3rd party libs
This build expects to find Underscore and Bean libraries as globals by
the time it is loaded. This is very useful for those how want to take
greater control of the libraries used.

Using this build RequireJS and Browserify users can manually setup a
shim configs for Flotr2.
Merge pull request #225 from epeli/nolibs

Add build without 3rd party libs
Merge branch 'master' of https://github.com/HumbleSoftware/Flotr2

Conflicts:
	js/types/lines.js
Fixe prob with infinite loop: be careful with JS vars visibility