Ignore files not ending with ",v" unless -P is on.
Revert "delete temporary files directly"

This failed on a conversion of the groff repository, leaving an empty
directory. To reproduce:

cvssync anonymous@cvs.savannah.gnu.org:/sources/groff groff
find groff | cvs-fast-export

Note the non-empty directory message.
Preparation for threaded scheduler.
Enable THREADS by default (but the thread scheduler ism't enabled yet).

All regression tests pass.
Ready to test threading.
Regression tests now pass with progress-report and atom-creation mutexes.
Narrow a variable scope.
Add instrumentation before thread testing.
Instrumentation reveals that pthread_cond_wait() is not waking up.

Non-threaded scheduler continues to pass regression tests.
Thread-based schedular passes regression tests.
Clean up a remnand mutex.
Thread schedular fix and documentation.
Explain a minor drawback odf threading.
More internals explanation.
Alas.  Thread scheduling has a bug.  Reverting to sequential.

All regression tests pass.
Serialization of snapshot number assignment is requred.
Pack all the edit-buffer globals in generate.c into a context structure.

All regression tests pass.
Each cvs_file object gets its own editbuffer instance.
Bring Gexpand inside the editbuffer structure.  All regression tests pass.
Add more instrumentation.