This change removes the cache in `DatabaseNodeImp` and simplifies the caching logic in `SHAMapStoreImp`. As NuDB and RocksDB internally already use caches, additional caches in the code are not very valuable or may even be unnecessary, as also confirmed during preliminary performance analyses.
This change renames all occurrences of `rippled.cfg` to `xrpld.cfg`. It also provides a script to allow developers to replicate the changes in their local branch or fork to avoid conflicts. For the time being it maintains support for `rippled.cfg` as config file, if `xrpld.cfg` does not exist.
