Add drupal7 VMOD.

R1/source/vmods/vmod_drupal7.json

+{
+    "name": "drupal7",
+    "date": "2016-07-21",
+    "desc": "Provide Drupal-related functions within Varnish",
+    "license": "FreeBSD",
+    "status": "mature",
+    "maintainer": "xavier.varnish@kindwolf.org",
+    "repos": "git://git.kindwolf.org/repo/libvmod-drupal7/",
+    "rev": {
+        "3.0": {
+            "url_vcc": "https://git.kindwolf.org/libvmod-drupal7/raw/3.0/src/vmod_drupal7.vcc",
+            "url_doc": "https://git.kindwolf.org/libvmod-drupal7/raw/3.0/README.rst"
+        },
+        "4.0": {
+            "url_vcc": "https://git.kindwolf.org/libvmod-drupal7/raw/4.0/src/vmod_drupal7.vcc",
+            "url_doc": "https://git.kindwolf.org/libvmod-drupal7/raw/4.0/README.rst"
+        }
+    }
+}