DERBY-6320 Log a page dump to derby.log if ERROR nospc: nospc.U is returned to the user
This patch adds the ability to dump a page in an insane build, and adds 2 calls to do so in 2 outstanding nospc error cases. In those two cases a new user
level error is thrown and nests the nospc.U error so that we still know the
original stack trace where the lowest error was thrown.  
The patch passes all tests and the specific errors were hand tested, one of 
them using the test case filed in DERBY-4923 and in the other case just by hand forcing the codepath.



git-svn-id: https://svn.apache.org/repos/asf/db/derby/code/trunk@1535075 13f79535-47bb-0310-9956-ffa450edef68