[UIMA-4159] fix error message, fix off-by-one in switching from intSet to other, fix computation of offset when switching from HashSet to IntBitSet, add test case which fails without the fix, and succeeds afterwards.

git-svn-id: https://svn.apache.org/repos/asf/uima/uimaj/trunk@1648102 13f79535-47bb-0310-9956-ffa450edef68