Fixes in the page range selection and verification logic.

1. Typing a range where the start is greater than the end was
   leading to a crash.

2. Typing the same single range, e.g. "2,2", was leading to a crash.

3. If two ranges are non-overlapping but consecutive they were
   not merged

4. Typing multiple times a digit that is less than the page count,
   e.g. page count "2" and typing "11", was not caught by the input
   verification.

bug:10812904

Change-Id: I754715b5d792a1a6c3a4f9f644edfa9aea7ac127