lldp support in Ansible

This PR introduces support for a lldp module.

lldpd is similar to CDP and can return useful details about a server's network like ports, switches, and VLANs.

library/net_infrastructure/lldp

+#!/usr/bin/python -tt
+# This file is part of Ansible
+#
+# Ansible is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# Ansible is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with Ansible.  If not, see <http://www.gnu.org/licenses/>.
+
+import subprocess
+
+DOCUMENTATION = '''
+---
+module: lldp
+short_description: get details reported by lldp 
+description:
+  - Reads data out of lldp
+
+author: Andy Hill
+notes:
+  - Requires lldpd running and lldp enabled on switches 
+'''
+
+def gather_lldp():
+    cmd = ['lldpctl', '-f', 'keyvalue']
+    proc = subprocess.Popen(cmd, stdout=subprocess.PIPE)
+    (output, err) = proc.communicate()
+    if output:
+        output_dict = {}
+        lldp_entries = output.split("\n")
+
+        for entry in lldp_entries:
+            if entry:
+                path, value = entry.strip().split("=", 1)
+                path = path.split(".")
+                path_components, final = path[:-1], path[-1]
+
+            current_dict = output_dict
+            for path_component in path_components:
+                current_dict[path_component] = current_dict.get(path_component, {})
+                current_dict = current_dict[path_component]
+            current_dict[final] = value
+        return output_dict
+            
+
+def main():
+    module = AnsibleModule({})
+
+    lldp_output = gather_lldp()
+    try:
+        data = {'lldp': lldp_output['lldp']}
+        module.exit_json(ansible_facts=data)
+    except TypeError:
+        module.fail_json(msg="lldpctl command failed. is lldpd running?")    
+   
+# this is magic, see lib/ansible/module_common.py
+#<<INCLUDE_ANSIBLE_MODULE_COMMON>>
+
+main()
+