ndn-tools unit tests

Assumptions

Unit tests for a tool foo should be placed in the folder foo and the build script for the tool should define foo-objects that includes all object files for that tool, except the object that contains the main() function.

For example:

def build(bld):
    bld.objects(
        target='tool-subtool-objects',
        source=bld.path.ant_glob('subtool/*.cpp', excl='subtool/main.cpp'),
        use='core-objects')

    bld.program(
        name='subtool',
        target='../../bin/subtool',
        source='subtool/main.cpp',
        use='tool-subtool-objects')

    bld(name='tool-objects',
        use='tool-subtool-objects')