ISOSegmentValidator: Create $(OBJDIR) if needed.
Remove unused tttemp variable which is breaking the build.
Remove 'dependencies' file from git, since it gets auto-generated, and don't print a warning if
it doesn't exist, since Make will recreate it anyway.
Ignore a bunch of files that shouldn't be checked in (.a, .exe, .o, etc.)
Make run_tests.sh executable.