DERBY-6237(PreparedStatement.execute() fails starting 10.2 when multiple rows are updated and PreparedStatement.setCharacterStream(int, Reader, int) is used)

This commit separates testing of setCharacterStream on CLOB and VARCHAR columns as 2 separate tests. This way failure of one data type will not mask the behavior of the other data type. 

I found through this test sparation that in 10.2, 
1)setCharacterStream on VARCHAR columns work fine(just like 10.1 release) for both one row and multi-row update through prepared statement. 
2)But setCharacterStream on CLOB column when update touches more than one row(in case of embedded only) fails in 10.2 release.



git-svn-id: https://svn.apache.org/repos/asf/db/derby/code/branches/10.2@1488606 13f79535-47bb-0310-9956-ffa450edef68