Strings: Extending the scope of the translations

Extracting strings from the program code to be able to extend the scope of the translations.

Work made by Paku (at #471) and comited by Arthur.

This is a squashed version of the following commits:
Attempt to recover lost ML changes
ML2: source correction
ML2: source correction 2
ML2: source correction 3
MLGUI2: MAVLink Error string, conected > connected
MLGUI2: little correction
MLGIU2: strings extraction ParamsFragment.java SettingsFragment.java