Merge pull request #25 from msgpack/feature/update_for_squeak6-2

- Use bitAnd: , bitOr: for compatibility

repository/MessagePack-Core.package/MpDecoder.class/instance/readTimestamp64..st

@@ -3,5 +3,5 @@ readTimestamp64: aStream
 	| nanosAndSeconds nanos seconds |
 	nanosAndSeconds := MpPortableUtil default readUint64From: aStream.
 	nanos := nanosAndSeconds >> 34.
-	seconds := nanosAndSeconds & 16r00000003ffffffff.
+	seconds := nanosAndSeconds bitAnd: 16r00000003ffffffff.
 	^MpPortableUtil default timestampFromSeconds: seconds nanos: nanos

repository/MessagePack-Core.package/MpEncoder.class/instance/writeTimestamp..st

@@ -6,5 +6,5 @@ writeTimestamp: timestamp
 	nanos := secondsArray at: 2.
 	(seconds >> 34) == 0 ifFalse: [ ^ self writeTimestamp96: seconds nanos: nanos ].
 	(nanos == 0 and: [seconds < 4294967296]) ifTrue: [ ^self writeTimestamp32: seconds ].
-	nanosAndSeconds := (nanos << 34) | seconds.
+	nanosAndSeconds := (nanos << 34) bitOr: seconds.
 	^self writeTimestamp64: nanosAndSeconds

repository/MessagePack-Squeak-Core.package/MpSqPortableUtil.class/instance/timestampFromSeconds.nanos..st

@@ -1,6 +1,15 @@
 actions
 timestampFromSeconds: seconds nanos: nanoSeconds
 	| microseconds ts |
-	microseconds := (seconds * 1000000) + (nanoSeconds * 0.001).
+	microseconds := seconds * 1000000.
+	nanoSeconds isZero ifFalse: [ | microsPart rem |
+		rem := nanoSeconds rem: 1000.
+		rem = 0 ifTrue: [
+			microsPart := nanoSeconds / 1000.
+		] ifFalse: [
+			microsPart := nanoSeconds * 0.001.
+		].
+		microseconds := microseconds + microsPart.
+	].
 	ts := DateAndTime utcMicroseconds: microseconds offset: 0.
 	^ts