TODO

   1 - port changes from recent versions of lttng kernel
   2 - update to trace format 2.5
   3 - make a trace testing script (that can assert whether a trace contains certain events)
   4 - make web site
   5 - make sure the proper structures are cacheline aligned, and test performance, including multi-threaded
   6 - use signal safe snprintf
   7 - test with smaller subbuffer sizes
   8 - fix header/lib priority problem at compilation
   9 - fix FIXME's in the code
  10 - make cli interface for flight recorder
  11 - make cli interface for changing subbuffer size and number
  12 - add \n at end of messages in communication protocol
  13 - save_registers: save them only when the marker is active (complicated because we need to know their value at the address that is put in struct marker)
  14 - make streaming work
  15 - ustd should work as a pool of threads
  16 - support multiple simultaneous traces