Feature checklist

[fvantienen]

This adds the option to add a checklist to your airframe which can be shown in the GCS. When an item is checked off or entered it is send to the on- and off board log.

An example checklist is:

    <checklist>
        <item name="pic" type="text">Enter the PIC</item>
        <item name="pac" type="text">Enter the PAC</item>
        <item name="gcs" type="text">Enter the GCS op</item>
        <item name="goal" type="text">Goal of the flight</item>
        <item name="basic law">Location, airspace and weather</item>
        <item name="RC Battery">Check the RC battery</item>
        <item name="tail connection">Check tail connection</item>
        <item name="wing tape">Check wings taped and secured</item>
        <item name="attitude">Check attitude and heading</item>
        <item name="takeoff location">Put UAV on take-off location</item>
        <item name="flight plan">Check flight plan</item>
        <item name="flight block">Switch to correct flight block</item>
        <item name="camera">Switch on camera</item>
        <item name="announce">Announce flight to other airspace users</item>
    </checklist>

[fvantienen]

@Fabien-B I changed the chatbubble layout also, because this way it doesn't have as much whitespace as before.
Though what is still really missing is like a small icon showing that you have received a message when the chat is closed on the chatbubble widget icon.

This also combines messages when they are received shortly after each other:

[dewagter]

Great update.

[fvantienen]

This also fixes #20

[fvantienen]

@Fabien-B can you check and merge this if you are ok?

[dewagter]

Works great for me.

[Fabien-B]

Nice addition!
Maybe it could be good to add a label in the checklist widget in the case there is no checklist in the airframe?
Something like

No checklist found in airframe.
You may need to update the setting 'Checks->ground_done' manually.