Add mochad component (#3970)

This commit adds a new component for communicating with mochad[1] a
socket interface for the CM15A and CM19A USB X10 controllers. This
commit leverages the pymochad library to interface with a mochad socket
either on a local or remote machine. Mochad is added as as a generic
platform because it supports multiple different classes of device,
however in this patch only the switch device implemented as a starting
point. Future patches will include other devices types. (although
that's dependent on someone gaining access to those)

[1] https://sourceforge.net/projects/mochad/

tests/helpers/test_config_validation.py

@@ -300,6 +300,18 @@ def test_temperature_unit():
     schema('F')
 
 
+def test_x10_address():
+    """Test x10 addr validator."""
+    schema = vol.Schema(cv.x10_address)
+    with pytest.raises(vol.Invalid):
+        schema('Q1')
+        schema('q55')
+        schema('garbage_addr')
+
+    schema('a1')
+    schema('C11')
+
+
 def test_template():
     """Test template validator."""
     schema = vol.Schema(cv.template)