Summary:
- Made CLI arguments take precedence over options file when both are provided. Note some of the CLI args are not settable via options file, like `--compression_max_dict_bytes`, so it's necessary to allow both ways of providing options simultaneously.
- Changed `PrepareOptionsForOpenDB` to update the proper `ColumnFamilyOptions` if one exists for the user's `--column_family_name` argument. I supported this only in the base class, `LDBCommand`, so it works for the general arguments. Will defer adding support for subcommand-specific arguments.
- Made the command fail if `--try_load_options` is provided and loading options file returns NotFound. I found the previous behavior of silently continuing confusing.
Closes https://github.com/facebook/rocksdb/pull/3144
Differential Revision: D6270544
Pulled By: ajkr
fbshipit-source-id: 7c2eac9f9b38720523d74466fb9e78db53561367
ed3af9ef99