Fixed stale build documentation.
Fixed stale build documentation.

Simplified and fixed stale build documentation to bring it in-line with
updates to Luna including:

  * Git repositories are automatically detected and configured by Luna.
  * Luna now bundles the m2e development support plugin.
  * Target sub-modules are not required to be imported into Eclipse
workspace.
rgladwell/m2e-android,WonderCsabo/m2e-android,rgladwell/m2e-android,b-cuts/m2e-android,b-cuts/m2e-android,WonderCsabo/m2e-android