hal: increase some limits

Increase name length from 41 to 47.  This accomodates some long
names in hostmot2, while also making (HAL_NAME_LEN+1) a multiple
of 8 to improve strucure packing.

Since names make up a substantial fraction of the total HAL shared memory
area use, increase HAL_SIZE by about 48/42, also rounding it to be a
multiple of 4096, the page size on all common systems.

When changing these sizes, the HAL version code has to be increased.

Signed-off-by: Jeff Epler <jepler@unpythonic.net>