Unify options with gfio

Add the parser features and unify the option table.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/fio.1 b/fio.1
index be0cf91..d197f7a 100644
--- a/fio.1
+++ b/fio.1
@@ -1034,7 +1034,7 @@
 .TP
 .BI lockmem \fR=\fPint
 Pin the specified amount of memory with \fBmlock\fR\|(2).  Can be used to
-simulate a smaller amount of memory.
+simulate a smaller amount of memory. The amount specified is per worker.
 .TP
 .BI exec_prerun \fR=\fPstr
 Before running the job, execute the specified command with \fBsystem\fR\|(3).