Update --help menu; Explain -O option and drop -L option

src/usage.c

@@ -79,7 +79,6 @@ static const char *USAGE_BIG[] =
   " -b, --benchmark               |      | Run benchmark                                        |",
   "     --speed-only              |      | Return expected speed of the attack, then quit       |",
   "     --progress-only           |      | Return ideal progress step size and time to process  |",
-  " -L, --length-limit-disable    |      | Disable optimizations for password- and salt-length  |",
   " -c, --segment-size            | Num  | Sets size in MB to cache from the wordfile to X      | -c 32",
   "     --bitmap-min              | Num  | Sets minimum bits allowed for bitmaps to X           | --bitmap-min=24",
   "     --bitmap-max              | Num  | Sets maximum bits allowed for bitmaps to X           | --bitmap-max=24",
@@ -89,6 +88,7 @@ static const char *USAGE_BIG[] =
   " -d, --opencl-devices          | Str  | OpenCL devices to use, separated with commas         | -d 1",
   " -D, --opencl-device-types     | Str  | OpenCL device-types to use, separated with commas    | -D 1",
   "     --opencl-vector-width     | Num  | Manually override OpenCL vector-width to X           | --opencl-vector=4",
+  " -O, --optimized-kernel-enable |      | Enable optimized kernels (limits password length)    |",
   " -w, --workload-profile        | Num  | Enable a specific workload profile, see pool below   | -w 3",
   " -n, --kernel-accel            | Num  | Manual workload tuning, set outerloop step size to X | -n 64",
   " -u, --kernel-loops            | Num  | Manual workload tuning, set innerloop step size to X | -u 256",