Make it compatible with 'template' gtwave files as found in openair's
repository.
The type VCD_NAME was added to the VCD IDs in T_messages.txt.
The database processing code was adapted to use it.
The tracer to_vcd was adapted to use it and render the produced vcd
output compatible with the 'template' gtkwave files.
When running to_vcd, do not forget to pass -vcd to use this feature.
the list of IDs is stored alphabetically so when accessing the database
with an ID one needs an indirection to get the correct record.
"pos" was not clear. "id_to_pos" is clearer.
Cedric Roux