configure debug target for native
check for active_thread != NULL in syscalls.c before using it

fixes #498
Fix my licensing
Merge pull request #587 from LudwigOrtmann/native_debug_target

configure debug target for native
Merge pull request #588 from LudwigOrtmann/issue_498

check for active_thread != NULL in syscalls.c before using it
Merge pull request #590 from authmillenon/licensing

Fix authmillenon's licensing