Prepare for a 1.9 release!

Changes

@@ -1,3 +1,15 @@
+Release 1.9 (2019-08-22):
+- Issue #50: add opam file, make it easy to "opam publish" new versions
+- Issue #38: configure detects 32bit OCaml switch on 64bit host
+- Fix #36: change Q.equal, leq, geq comparisons for undef
+- Request #47: move infix comparison operators of Z in submodule,
+  avoid shadowing the polymorphic compare
+- Fix #49: INT_MAX undeclared
+- Request #46: add prefixnonocaml option ()
+- Request #45: fix ocamllibdir/caml/mlvalues.h bug (Cygwin)
+- Fix: attempting to build numbers too large for GMP raises an OCaml exception
+  instead of crashing with "gmp: overflow in mpz type"
+
 Release 1.8 (2019-03-30):
 - Request #20: infix comparison operators for Q and Z [Max Mouratov]
 - Request #39: gdc(x,0) = gcd(0,x) = x [Vincent Laporte]

META

@@ -1,11 +1,11 @@
 description = "Arbitrary precision integers"
 requires = ""
-version = "1.8"
+version = "1.9"
 archive(byte) = "zarith.cma"
 archive(native) = "zarith.cmxa"
 
 package "top" (
-  version = "1.8"
+  version = "1.9"
   description = "ZArith toplevel support"
   requires = "zarith"
   archive(byte) = "zarith_top.cma"