Allow catching exceptions from threads
    
    By running exception handler every time an exception appears in a thread we
    block us from using our features provided by the wait method. Some exceptions
    may be non-critical and the waiting thread may recover from the erroneous state.
    However, we need to give it a chance to do so.
    
    The wait_all method called before we start the actual installation should make
    sure there are no abandoned problematic threads that raised exception nobody
    cared about.