Implement basic queue for sending multiple commands

Sends dbus signal upon completion of command

Change-Id: Ic507f35af0b38305eecd5558c55738f2d283aac5
Signed-off-by: Andrew Geissler <andrewg@us.ibm.com>
diff --git a/xyz/openbmc_project/Control/Internal/Host.errors.yaml b/xyz/openbmc_project/Control/Internal/Host.errors.yaml
new file mode 100644
index 0000000..3c14863
--- /dev/null
+++ b/xyz/openbmc_project/Control/Internal/Host.errors.yaml
@@ -0,0 +1,3 @@
+- name: QueueEmpty
+  description: The host response queue is empty and it should not be!
+