Use descriptive error messages for MergeValidationExceptions

These are no longer tied to CommitMergeStatus, so we can actually say
what we mean rather than picking a similar-sounding status enum out of
a hat.

Change-Id: I7d1429c885a99503fe8cdfa8fe8925e7125fcb35
1 file changed
tree: ea402a94b835e6b69896362685f0a095b30b93e4
  1. lib/
  2. src/
  3. .buckconfig
  4. .gitignore
  5. BUCK
  6. LICENSE
  7. pom.xml