Added .gitignore. Made gcache_rb_test cleanup after itself.
Updated .gitignore to ignore more transient files.
Fixed runtime change of cert.log_conflicts to not return a false error
More updates to .gitignore
Refs #8: fixes free space estimate in RingBuffer::seqno_reset()
Merging a fix for #8 from 2.x
Refs #8: 3.x-specific fixes: wrong seqno passed to RingBuffer::seqno_release()