RTF insert is made into an empty paragraph. To do that, two splits
are made before the insert, but only one is reverted afterwards.
This patch removes the second.

Also fixes a memory leak from unreleased heap object

The corresponding unit test is corrected. It was incorrect
because \par doesn't begin new paragraph; it only ends paragraph.
If a RTF is ended with \par } then no newline is added to its end.
The old unit test only worked because of the bug fixed by this
patch. Correct way of inserting new paragraph in the end of a RTF
is \par \par}

Change-Id: I63d50a940d7960beb35f7d774c833ed8499acbef