On some hosts, compilations with the T tracer was failing.

The error was:
  common/utils/T/T.h:15:19: fatal error: T_IDs.h: No such file or directory

The problem was that in CMakeLists.txt some targets depend on the
pre-generation of T_IDs.h but this dependancy relation was not set,
so those targets could be generated before the T (it was the case
with HASHTABLE).

This commit fixes that. Basically, we take all the targets found in
"add_executable" and "add_library" and make them depend on the
T if the T is enabled. Almost all existing targets were added,
even those that may not need it.

The problem of this approach is that someone adding a new target
using the T will not necessarily add a dependancy there.

Another solution would be to generate T_IDs.h at "cmake" stage,
not "make" stage and use an "if (NOT EXISTS T_IDs.h)" to generate
the file. We lose the dependancy relation though.

Things may be changed if maintenance cost is too high.