Refines jsonsuite/customsuite make targets
Refines jsonsuite/customsuite make targets

Cleans up the makefile a bit, refines the targets:

  * You can now target specific tests with jsonsuite.<testname>.
    Our custom tests are jsonsuite.custom/<testname>

    eg:  make jsonsuite.allOf
         make jsonsuite.custom/anyOf

  * Fixes the dependencies so `make jsonsuite.allOf` will also build
    jvst

  * Cleaner targets for running json/custom/all suites:

    jsonsuite           only JSON schema test suite
    customsuite         our custom tests
    allsuites           both jsonsuite and customsuite

sfstewman/jvst,katef/jvst,katef/jvst,sfstewman/jvst