S allius/issue395 (#399)

* add button for languages setting

* build a web module for the dashboard

- load all python module from local dir
- initialize Blueprint and Babel

* set a default key for secure cookies

* add translations to docker container

* improve translation build  

- clean target erases the *.pot
- don't modify the resurt of url_for() calls
- don't translate the language description

* translate connection table, fix icon

* build relative urls for HA ingress

* fix unit test, increase coverage

Makefile

@@ -1,11 +1,19 @@
 .PHONY: build babel clean addon-dev addon-debug addon-rc addon-rel debug dev preview rc rel check-docker-compose install
 
-babel debug dev preview rc rel:
+babel:
 	$(MAKE) -C app $@
 
-clean build:
+build:
 	$(MAKE) -C ha_addons $@ 
 
+clean build:
+	$(MAKE) -C app $@
+	$(MAKE) -C ha_addons $@ 
+
+debug dev preview rc rel:
+	$(MAKE) -C app babel
+	$(MAKE) -C app $@
+
 addon-dev addon-debug addon-rc addon-rel:
 	$(MAKE) -C app babel
 	$(MAKE) -C ha_addons $(patsubst addon-%,%,$@)