Omit the -Xlint:all compiler argument (enabling warnings) for branches other than the development branches (currently JDK8).
This is because older compilers produce more warnings than the newer ones, especially in aspects related to parameterized types,
because newer compilers have more advanced type inferences. So we concentrate our attention on the warnings produced by latest javac only.


git-svn-id: https://svn.apache.org/repos/asf/sis/branches/JDK7@1595044 13f79535-47bb-0310-9956-ffa450edef68