Rationalize the way architecture-specific sub-components are built with ant in branch-1

Three different compile flags, compile.native, compile.c++, and compile.libhdfs, turn on or off different architecture-specific subcomponent builds, but they are generally all off or all on and there's no evident need for three different ways to do things. Also, in build.xml, jsvc and task-controller are included in targets "package" and "bin-package" as sub-ant tasks, while librecordio is included as a simple dependency. We should work through these and get them done in one understandable way.

This is a matter of maintainability and understandability, and therefore robustness under future changes in build.xml. No substantial change in functionality is proposed.