Fix bash variable input (#207)

* Fix bash variable input

This will cause error in validation.
i have tried with 
if ! msg="$(tdtool --"$input")"; then
if ! msg="$(tdtool --"${input}")"; then
if ! msg="$(tdtool --${input})"; then
without success.
The only one i got working in real life is the one in this PR.

* Trying variable with curlies

Changed frm only output errors to output all output from tdtool. 
Enables listing of devices and sensors with output to add-on log.

* Update config.json

* fix not used exec

* fix lint

* update output

tellstick/config.json

@@ -1,6 +1,6 @@
 {
   "name": "TellStick",
-  "version": "0.2",
+  "version": "0.3",
   "slug": "tellstick",
   "description": "TellStick and TellStick Duo service.",
   "url": "https://home-assistant.io/addons/tellstick/",