Get Rid of nobuild, nolink, and alldeps (#2765)

* Removing the nobuild, nolink, and alldeps dependency types in favor of being explicit.
* This will help with maintenance going forward, as adding more dependency types won't affect existing declared dependencies in weird ways.
* default deptype is still `('build', 'link')`

var/spack/repos/builtin/packages/py-autopep8/package.py

@@ -38,7 +38,7 @@ class PyAutopep8(Package):
     extends('python', ignore='bin/pep8')
     depends_on('python@2.6:2.7,3.2:')
 
-    depends_on('py-pycodestyle@1.5.7:1.7.0', type=nolink)
+    depends_on('py-pycodestyle@1.5.7:1.7.0', type=('build', 'run'))
 
     depends_on('py-setuptools', type='build')