Just to avoid the confusion of having 2 things with the same name
without a clear reason

Feedback from Guilhem Saurel.

Based on feedback from G. Saurel.

  - when signal value contained a space, only the part before the space
    was stored in the signal.
  - add a test on this case.

  Default implementation adds std::endl at the end of the stream.
  In the case of string this extra '\n' is not desired.

  When type is string and input istringstream contains an empty string,
  operator>> make method fail return true.
  This commit overcome this issue by not testing the result.

Fix debug-tracer.cpp

Add TimeDependency::addDependencies + doc of SignalTimeDependent