Extracting strings from the program code to be able to extend the scope of the translations.

Work made by Paku 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
updating the project to make use of the V4 support library in order to improve backward compatibility.
Help: Changing the menu system to have a global menu definition

Added the help item to this global definition, and created an empty dialog for the help.
Help: Added functionality to the help menu item
Help: New way for Activities to inform the help videos they own
Help: Moving all the help menu related stuff to a new super class
updated the droidplanner project to make use of the support library.
propagated necessary changes, and exported SettingsFragment to a different activity since it's not yet supported by the support library.
fixed fragments handling bugs.
merged with latest from upstream/master.
fixed remaining issues with switch to the support library.
updated remaining fragments to the v4 support library.
Merge branch 'master' into StringsExtraction

Conflicts:
	DroidPlanner/res/values/strings.xml
Merge pull request #479 from DroidPlanner/StringsExtraction

Strings: Extending the scope of the translations
Merge pull request #551 from arthurbenemann/YoutubeGuides

Youtube video guides
typo correction
Merge pull request #555 from Paku-/failsafe_fasil

typo correction
updating submodules with latest from upstream/master.
Mission: Adding a new event to indicate that a new mission has been received
Mission: Request the drone mission when arming.
Mission: Fixing bug in the Home object
Mission: Removed debug code.

The home icon loaded missions, but now we have that functionality via the menu.