Just about any of the popular free source control tools should do the job - you can integrate them with CB via the Tools menu. I use Tortoise Subversion (which is great) and have, for example, this entry in my tools configuration to do a project commit:
Name: Commit:
Executable: TortoiseProc.exe
Parameters: /command:commit /path:${PROJECT_DIR}
Working directory:
and this one to do a file diff:
Name: Diff
Executable: TortoiseProc.exe
Parameters: /command:diff /path:${ACTIVE_EDITOR_FILENAME}
Working directory: