handle component groups like physics

[ngokevin]

This allows multiple related components / systems to be registered from a single file.

• s/name/names. This can be a single component name or an array.

What the Inspector should do:

• For each package entry, populate the dropdown with every component name. Instead of appending component.name, concatenate component.names.
• When injecting the <script>, check whether another related component has already injected it. For example, if we have already injected physics-body, then physics-joint will also have been registered from the same file, and the Inspector doesn't need to do anything. This perhaps already works.

aframe-audioanalyser:
  names: [audioanalyser, audioanalyser-waveform, audioanalyser-levels, audioanalyser-beats]
  versions:
    0.3.0:
      version: ^5.5.3
      path: dist/aframe-audioanalyser-components.min.js

aframe-physics:
  names: [physics-body, physics-joint]
  versions:
    0.3.0:
      version: ^2.5.3
      path: dist/aframe-extras.physics.min.js

aframe-leapmotion:
  names: [leapmotion-hands, leapmotion-grab]
  versions:
    0.3.0:
      version: ^3.2.3
      path: dist/aframe-leapmotion.min.js