Improve Pan language support (#3691)

* Add a larger set of sample files for Pan

This is a fairly good cross section of Pan based on code from:
* https://github.com/quattor/template-library-examples
* https://github.com/quattor/template-library-core

* Add Pan language grammar

samples/Pan/infernalis.pan

@@ -0,0 +1,22 @@
+unique template site/ceph/server/infernalis;
+
+include 'components/dirperm/config';
+
+"/software/components/dirperm/paths" = {
+    foreach (idx; mp; value('/system/filesystems')) {
+        if (match(mp['mountpoint'], format('^%s', CEPH_OSD_MP_BASE))) {
+            append(SELF, dict(
+                "path", mp['mountpoint'],
+                "owner", "ceph:ceph",
+                "perm", "0755",
+                "type", "d",
+            ));
+        };
+    };
+    SELF;
+};
+
+include 'common/sysctl/service';
+prefix "/software/components/metaconfig/services/{/etc/sysctl.conf}/contents";
+
+'kernel.pid_max' = 4194303;