Massive conversion from Package to AutotoolsPackage (#2845)

* Massive conversion from Package to AutotoolsPackage

* Forgot to convert p4est to AutotoolsPackage

* Fix typo

* Fix broken link in docs

var/spack/repos/builtin/packages/sdl2-image/package.py

@@ -25,7 +25,7 @@
 from spack import *
 
 
-class Sdl2Image(Package):
+class Sdl2Image(AutotoolsPackage):
     """SDL is designed to provide the bare bones of creating a graphical
     program. """
 
@@ -35,9 +35,3 @@ class Sdl2Image(Package):
     version('2.0.1', 'd94b94555ba022fa249a53a021dc3606')
 
     depends_on('sdl2')
-
-    def install(self, spec, prefix):
-        configure('--prefix={0}'.format(prefix))
-
-        make()
-        make('install')