Full-text search benchmark.

Before compilating, edit Makefile for RDBMS set and
paths to its.

Init example:
./ftsbench -i -n 10000 -f gin -g pgsql -d contrib_regression

Benchmark example:
./ftsbench -c 10 -n 300 -f gin -g pgsql -d contrib_regression


PostgreSQL prerequisite:
	version >= 8.2
	./configure --enable-thread-safety
	contrib/tsearch2

MySQL prerequisite:
	tested on 5.0.24a
	./configure --enable-thread-safe-client --with-pthread