* Add TraceOutput::PrintArgs(), a va_list version of Print().
* Move code of TraceOutput::Print() to new private template function
print_stack_trace().
* Add public tracing_print_stack_trace().
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@43085 a95241bf-73f2-0310-859d-f6bbb57e9c96