Dirty crash when exiting safety bounds

[JoshuaHaustein]

When performing a software-emergency stop (e.g. due to exiting the safe workspace region, defined in constants.h), the stop_all function currently calls std::exit. This behaviour is rather undesirable, as it leads to a std::system_error being thrown and prevents higher level-code from cleaning up.

I think it would be nicer to throw a custom exception that higher-level code can catch to clean up and print useful error messages. The current error message that is printed when violating workspace limits is:

terminate called after throwing an instance of 'std::system_error
what(): Resource deadlock avoided

which is rather misleading. A potential reason for this error could be this.

See also ROS guidelines about the use of exit