Changes:

1 intarray: bugfix for int[]-int[] operation
2 intarray: split _int.c to several files (_int.c now is unused)
3 ntarray (gist__intbig_ops opclass): use special type for index storage
4 ltree (gist__ltree_ops opclass), intarray (gist__intbig_ops): optimize
GiST's
penalty and picksplit interface functions, now use Hemming distance.

Teodor Sigaev