Refactor basebuild / allow apps without Application module

 Refactor basebuild template into "base-build" and "base-application",
 so that base-build does not force creation of a _MODULE_/Application
 directory:

- Rename templates/basebuild to templates/base-build
- Create templates/base-application
- Move templates/base-build/_MODULE_ to
  templates/base-application/_MODULE_
- Update <template> directives in dependent samples

Update Wear template so that it doesn't force creation of a
_MODULE_/Application directory:

 - Remove templates/Wear/_MODULE_

Bug: 18353265
Change-Id: Ie35cc651c49bd7e3f22a6044c352a9acbd17ecf2