syncbase/vsync: DAG improvements & more tests.

* Support conflict detection where the DAG fragments have no
  common ancestor (evolved from disjoint pasts).
* Switch sync tests to using leveldb instead of memstore.
* Guard the random number generator with a mutex.
* Add more DAG tests.

Change-Id: Ic46ce0109cde04d8b4eaa93ae001ee28b2a65d12
13 files changed
tree: 452cb5de9e7d69d68a85fc7ec7f9bfd98619ca1d
  1. v23/
  2. x/
  3. .gitignore
  4. AUTHORS
  5. CONTRIBUTORS
  6. LICENSE
  7. PATENTS
  8. VERSION