* Rename variables so it's clearer what they do
* Fully document zebra-checkpoints arguments
* Remove some outdated references to zcashd
* Add a json-conversion feature for converting JSON to valid Heights
* Simplify zebra-checkpoints code using conversion methods
* Track the last checkpoint height rather than the height gap
* Move all the CLI-specific code into a single function
* Remove cfg(feature) from the test RPC client API
* Move the RpcRequestClient into zebra-node-services
* Fix the case of RpcRequestClient
* Add transport and addr arguments to zebra-checkpoints
* Make zebra-checkpoints support both CLI and direct JSON-RPC connections
* Fix RpcRequestClient compilation
* Add a suggestion for zcashd authentication failures
* Document required features
* Handle differences in CLI & direct parameter and response formats
* Replace a custom function with an existing dependency function
* Add a checkpoint list test for minimum height gaps
teor