Replace delete in favor of setting to undefined to prevent V8 deoptimization.
Prevent V8 "assignment to parameter in arguments object" deoptimizations.

Some getter-like functions still need fixing, but this might require a fix in Straps.js first.
Execute PaperScript using new Function() rather than eval() and with() {}

This results in some impressive speeding improvements, as modern JS engines are finally able to optimize the resulting code.
Merge branch 'refs/heads/paperscript-refactoring' into v8-optimizations
Change the way PaperScripts are executed in Node.js

Requiring a PaperScript returns an initialize method which receives the Canvas argument.
Update to latest Prepro.js that exposes all globals.
Instead of creating the actual canvas we can also just provide a size.
Bail out of Item#transform() immediately if there is nothing to do.
Shorten code a bit.
Updated README.md to include instructions for installation on Ubuntu/Debian Linux.
1. Added cd into cloned directory.
2. Add push to remote origin as part of submitting a patch
Merge branch 'refs/heads/paperscript-refactoring'

Conflicts:
	src/core/PaperScope.js
Clean up code and comments.
Fix comments.
Update copyright notice.
Fix bounds check for mousemove events.

Closes #369
Merge pull request #381 from bmacnaughton/README.md-update

Readme.md update
Simplify Debian/Ubuntu instructions a bit.
Some more streamlining of README instructions.
Remove internal clamping of color values to facilitate proper mathematical calculations with colors.

Clamp only when producing CSS values. Closes #271.