Split client and server plugin functionality.

There is virtually no shared code for the client, extract it into its own
module and do away with the switches.

src/static/js/pluginfw/shared.js

@@ -0,0 +1,61 @@
+var _ = require("underscore");
+
+function loadFn(path, hookName) {
+  var functionName
+    , parts = path.split(":");
+
+  // on windows: C:\foo\bar:xyz
+  if (parts[0].length == 1) {
+    if (parts.length == 3) {
+      functionName = parts.pop();
+    }
+    path = parts.join(":");
+  } else {
+    path = parts[0];
+    functionName = parts[1];
+  }
+
+  var fn = require(path);
+  functionName = functionName ? functionName : hookName;
+
+  _.each(functionName.split("."), function (name) {
+    fn = fn[name];
+  });
+  return fn;
+};
+
+function extractHooks(parts, hook_set_name, normalizer) {
+  var hooks = {};
+  _.each(parts,function (part) {
+    _.chain(part[hook_set_name] || {})
+    .keys()
+    .each(function (hook_name) {
+      if (hooks[hook_name] === undefined) hooks[hook_name] = [];
+
+      var hook_fn_name = part[hook_set_name][hook_name];
+
+      /* On the server side, you can't just
+       * require("pluginname/whatever") if the plugin is installed as
+       * a dependency of another plugin! Bah, pesky little details of
+       * npm... */
+      if (normalizer) {
+        hook_fn_name = normalizer(part, hook_fn_name);
+      }
+
+      try {
+        var hook_fn = loadFn(hook_fn_name, hook_name);
+        if (!hook_fn) {
+          throw "Not a function";
+        }
+      } catch (exc) {
+        console.error("Failed to load '" + hook_fn_name + "' for '" + part.full_name + "/" + hook_set_name + "/" + hook_name + "': " + exc.toString())
+      }
+      if (hook_fn) {
+        hooks[hook_name].push({"hook_name": hook_name, "hook_fn": hook_fn, "hook_fn_name": hook_fn_name, "part": part});
+      }
+    });
+  });
+  return hooks;
+};
+
+exports.extractHooks = extractHooks;