add more testcases for date parsing

tests/test-parse-date

@@ -11,4 +11,6 hg backout --merge -d "2006-04-15 13:30
 hg ci -d "1150000000 14400" -m "rev 4 (merge)"
 echo "fail" >> a
 hg ci -d "should fail" -m "fail"
+hg ci -d "100000000000000000 1400" -m "fail"
+hg ci -d "100000 1400000" -m "fail"
 hg log --template '{date|date}\n'

tests/test-parse-date.out

@@ -6,6 +6,12 1 files updated, 0 files merged, 0 files
 abort: invalid date: 'should fail'
 transaction abort!
 rollback completed
+abort: date exceeds 32 bits: 100000000000000000
+transaction abort!
+rollback completed
+abort: impossible time zone offset: 1400000
+transaction abort!
+rollback completed
 Sun Jun 11 00:26:40 2006 -0400
 Sat Apr 15 13:30:00 2006 +0200
 Sat Apr 15 13:30:00 2006 +0000