Pre-prepare for hovercards

Summary:
D5120 and followups refactor and generalize object references in Remarkup -- notably, they move remarkup rules from a central location to the implementing applications.

Preserve blame by doing moves/renames only first. This change moves application remarkup rules into those applications, and renames the ones D5120 modifies.

Test Plan: Typed some preview text into a textarea, got a valid Remarkup render.

Reviewers: vrana, chad

Reviewed By: vrana

CC: aran

Differential Revision: https://secure.phabricator.com/D5123

src/applications/paste/remarkup/PhabricatorPasteRemarkupRule.php

@@ -0,0 +1,13 @@
+<?php
+
+/**
+ * @group markup
+ */
+final class PhabricatorPasteRemarkupRule
+  extends PhabricatorRemarkupRuleObjectName {
+
+  protected function getObjectNamePrefix() {
+    return 'P';
+  }
+
+}