This patch updates the lxt_write.h and lxt2_write.h header files
to the latest ones from GTKWave CVS. It also adds HAVE_INTTYPES_H
to the vpi_config.h.in header.
This patch updated the four file lxt_write.{c,h} and
lxt2_write.{c,h} to the latest ones from GTKWave. This
required adding the wavealloc.h include file and an
update to configure.in and vpi/vpi_config.h.in to add
checks/definitions for ALLOCA and FSEEKO.