DERBY-6518: JVMInfo should not use parseFloat() to parse java.specification.version

Change the parse logic so that it recognizes that version 1.10 is greater than 1.9.

git-svn-id: https://svn.apache.org/repos/asf/db/derby/code/trunk@1581777 13f79535-47bb-0310-9956-ffa450edef68