Feature request

Is your feature request related to a problem? Please describe.
When we raise an internal error it may be quite some time before we get something in the dataflash log or in the mavlink stream. This makes it harder to correlate internal errors with codepaths.

Describe the solution you'd like
Emit a statustext and/or log message when we detect an internal error has

Hi, I got a problem similar to #804.

My bridge did not connect correctly.
I have followed the latest tutorial and build Apollo successfully today.
My apollo did not connect in the following step.

Launch bridge (inside docker container):
./scripts/bridge.sh

I would need to add sudo in order to start my bridge.sh.
After adding that, there was no information print out from the terminal.

void AStarExpansion::add(unsigned char* costs, float* potential, float prev_potential, int next_i, int end_x,  int end_y)
{
    .........
    if(costs[next_i]>=lethal_cost_ && !(unknown_ && costs[next_i]==costmap_2d::NO_INFORMATION))
        return;
    potential[next_i] = p_calc_->calculatePotential(potential, costs[next_i] + neutral_cost_, next_i, prev_potential);
     .......
}

It is good that supervisor.getFromDef will seek out a node with the given DEF-name at any level of the scene tree. So, e.g., if I have one robot with a solid LEFT_WHEEL, I can use getFromDef('LEFT_WHEEL') to get that node, without needing to worry about whatever intervening ancestor nodes might lie above it.

Sometimes you'll have multiple nodes with the same DEF-name in the scene tree, e.g., i