This patch adds two versionning functions, described in the README.md file. They allow to kind of 'poll' for new versions of configuration on a given table, without needing to read the entire table to know if there is new material. This is especially useful when using the all/1 function to do further processing somewhere else based on some configuration data.
In some circumstances where bertconf still is the mechanism used but the config data needs further treatment, it should be possible to fetch entries without knowing the key. This patch adds a new function to fetch the entire content of a table, batched by chunks of 500 to avoid locking up a scheduler for too long on copying data. A single list with all entries is returned to the user. The value is not configurable for now -- if there is a need for it, the code can be extended to allow it.