vm-config: Allow platforms to construct their own classpath arguments.
In particular, DalvikPlatform now uses "-Djava.class.path=$cp"
instead of "-cp $cp" which didn't work with the app_process custom vm.
This enables caliper to test/benchmark Android framework-dependent code
(e.g. any typical application code) without needing to depend on a
specific version of Android which has an updated app_process binary.
Test: vogar --benchmark --mode app_process \
4 files changed