* Declare support for long polling in the getblocktemplate RPC
* Add long polling input and ID structs
* Split out an update_checksum() function
* Implement LongPollId conversion to and from a string
* Use the LongPollId type in the RPC
* Add a longpollid field to the getblocktemplate parameters and responses, but don't use it yet
* Use multiple RPC threads with the getblocktemplate feature, to enable efficient long polling
* Update RPC snapshots
* Remove the "longpoll" capability, it's for miners, not nodes
* Use the long poll length constant in tests
* Update snapshots
* Remove the "long polling is not supported" error
* Fix minor compilation issues after the merge/rebase
* Expand long poll id comments
* Rename estimated height to local height, because that's what it actually is
* Add an invalid params test and fix the long poll id test
* Add modified config for config_tests
* Instrument all the config sub-tests
* Show the missing config file when the test fails
* Fix the generated config file
* Allow a clippy lint in tests
* Explain conversion from bytes to u32
* Remove a duplicate test case
teor