Zepto.qsa & some other ternary operator changes

I mentioned in #623 that I would submit a pull request that reduced the number of ternary operators that we use inside Zepto. 

Here are two of these changes.

Uglify.js seems to be smart enough to inline if statements into ternary operators when they are used to build return statements, but it isn't smart enough to inline variables into ternary operators.

The code/style guide reflects these changes.