templater: add context.preload(t) to test if the specified template exists
I'm going to remove 'templ' from the resources dict because it is the only
resource that the caller can't provide. This also implies that putting
'templ' into the resources dict creates a reference cycle.
context.preload(t) will be used in place of templater.__contains__().
#require clang-libfuzzer test-repo
$ cd $TESTDIR/../contrib/fuzz
$ make
Just run the fuzzer for five seconds to verify it works at all.
$ ./bdiff -max_total_time 5