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.
Merge branch 'refs/heads/paperscript-refactoring' into v8-optimizations
Merge branch 'refs/heads/master' into v8-optimizations

Conflicts:
	src/core/Base.js
	src/style/Color.js
Use changes in latest Straps.js to remove as many hidden parameters as possible.

Hidden parameters through arguments[] are bad news for JS optimizer engines.
Merge branch 'refs/heads/master' into v8-optimizations
Remove the need for arguments[0] in bounds getters.
Remove need for arguments[1] in Item#transform()
Move Curve#getLength(from, to) to Curve#getPartLength(from, to).

Clears up the Curve#getLength() getter and removes the need for accessing arguments[]
Rearrange Base.read argument sequence.

options are used more often than length.
Remove unused arguments._read value and rename _index to __index.