#50 Message when it does'nt find an engine

[Pierre Boulenguez]

Add an explicit message in the console when eboard can not find an engine.

[Pierre Boulenguez]

Logged In: YES
user_id=1382166
Originator: YES

as first approach, added this :

global.output->append(_("Failed to run engine."),global.Colors.TextDefault,IM_NORMAL);
global.output->append(_("Error while running the command :"),global.Colors.TextDefault,IM_NORMAL);
global.output->append(FullCommand, global.Colors.TextDefault,IM_NORMAL);
{

in the int XBoardProtocol::loadEngine() function