Correct PersonIdent hashCode() and equals() to ignore milliseconds

Git doesn't store millisecond accuracy in person identity lines,
so a line that we create in Java and round-trip through a Git object
wouldn't compare as being equal.  Truncate to seconds when comparing
values to ensure the same identity is equal.

Change-Id: Ie4ebde64061f52c612714e89ad34de8ac2694b07
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

org.eclipse.jgit/src/org/eclipse/jgit/lib/PersonIdent.java

@@ -268,7 +268,10 @@ public class PersonIdent {
 	}
 
 	public int hashCode() {
-		return getEmailAddress().hashCode() ^ (int) when;
+		int hc = getEmailAddress().hashCode();
+		hc *= 31;
+		hc += (int) (when / 1000L);
+		return hc;
 	}
 
 	public boolean equals(final Object o) {
@@ -276,7 +279,7 @@ public class PersonIdent {
 			final PersonIdent p = (PersonIdent) o;
 			return getName().equals(p.getName())
 					&& getEmailAddress().equals(p.getEmailAddress())
-					&& when == p.when;
+					&& when / 1000L == p.when / 1000L;
 		}
 		return false;
 	}