Refactor pre-Doxy siphon scripts; VPP-396

- Modularize the code to make the Siphon process easier to
  maintain.
- Move much of the output rendering into Jinja2 templates.
- Add syscfg siphon type for startup config documentation.
- Add sample syscfg documentation.
- Add clicfg and syscfg preamble docs, adapted from their wiki pages.
- Fix sorting of CLI items across multiple directories.

Change-Id: Ib8288fe005adfea68ceed75a38ff8eba25d3cc79
Signed-off-by: Chris Luke <chrisy@flirble.org>

doxygen/siphon/process_clicmd.py

@@ -0,0 +1,56 @@
+# Copyright (c) 2016 Comcast Cable Communications Management, LLC.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at:
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# Generate clicmd formatted output
+
+import process, parsers
+
+class SiphonCLICMD(process.Siphon):
+
+    name = "clicmd"
+    identifier = "VLIB_CLI_COMMAND"
+
+    def __init__(self, *args, **kwargs):
+        super(SiphonCLICMD, self).__init__(*args, **kwargs)
+        self._parser = parsers.MacroInitializer()
+
+
+    # Output renderers
+
+    def index_sort_key(self, group):
+        _global = self._cmds['_global']
+        if group not in self._group:
+            return group
+        (directory, file) = self._group[group]
+
+        if file in _global and 'group_label' in _global[file]:
+            return _global[file]['group_label']
+
+        if directory in _global and 'group_label' in _global[directory]:
+            return _global[directory]['group_label']
+
+        return group
+
+    def item_sort_key(self, item):
+        return item['value']['path']
+
+    def item_label(self, group, item):
+        return "_".join((
+            self.name,
+            self.sanitize_label(self._cmds[group][item]['value']['path'])
+        ))
+
+
+# Register our processor
+process.siphons["clicmd"] = SiphonCLICMD