Drop SHARED_PROJECTS_DIR setting
Drop SHARED_PROJECTS_DIR setting

This is not used anywhere at all, and I am moving away from the "shared
projects" approach in favor of more use of Git submodules. That is,
instead of:

  project-1 (in SHARED_PROJECTS_DIR)
  framework-1 (in SHARED_PROJECTS_DIR)
  framework-2 (in SHARED_PROJECTS_DIR)

I am moving towards:

  project-1
  project-1/framework-1 (as submodule)
  project-1/framework-2 (as submodule)

Signed-off-by: Wincent Colaiuta <c76ac2e9cd86441713c7dfae92c451f3e6d17fdc@wincent.com>

wincent/buildtools,wincent/buildtools,wincent/buildtools