Determine cwd in exec_anatomy test at runtime.
Use APPLE CMake variable instead of __APPLE__ to decide what
environment variables to use.
Have CMake detect _NSGetEnviron() and use it if found.
Rename the state flag already_reported and move the decision to
report into report_call() and the setting of the flag into report().
Add support for execvP() function.
Merge pull request #24 from breser/porting_to_osx

Improvements to OS X Port