Add phpcs to analyze, display inline results on validate.

[grayside]

• Adds phpcs as currently constituted as a validate task.
• Adds phpcs:validate as an operation to the validate task. Defaults to "summary" but can be overridden in config. Displays results in terminal.
• Retains phpcs:drupal for backwards compatibility.
• Adds phpcs:inspect for more detailed reporting with the "full" format.
• For reasons of code-flow & variable scope, recombines the analyze & validate files as "quality.js".

This fixes #1

I wanted to handle #18 as well, but using the ruleset as defined by the Coder module the granularity of errors is very flat, hence the addition of the "inspect" target for deeper reporting. I imagine we'll want to use inspect for a watch variant, but leaving that for #13.

[grayside]

After further consideration, renamed inspect to full for more intuitive naming, added gitblame and summary as explicit options.

[grayside]

I'll spend some time fixing conflicts after some positive feedback. @arithmetric, think this is good to go?