12e264d58f
Adds support for a configurable set of trusted directories to search executables in (exec_dirs), which defaults to system PATH. If your filter specifies an exec_path that doesn't start with '/', then it will be searched in exec_dirs. Avoids having to write multiple filters to care for distro differences. Fixes bug 1079723. Also returns a specific error rather than try to run absent executables. Change-Id: Idab03bb0be6832a75ffeed4e78d25d0543f5caf9