* Fixed: [very slow execution of load_set_file #288](https://github.com/clicon/clixon/issues/288)
* New `clixon-lib@2021-11-11.yang` revision
* Modified option: RPC stats extended with YANG stats
* Modified `clixon-config@2021-11-11.yang` revision
* Added option:
* CLICON_PLUGIN_CALLBACK_CHECK
* Enable to make plugin context check before and after all callbacks.
* Added statistics for YANG: number of objects and memory used
* Use the treeref no-copy option of CLIgen to reduce memory
* Refactored cli-generation/autocli-start code
* Refactored cligen glue functions to use cligen_eval directly (remove clicon_eval,clixon_cligen_eval)
* Stricter checking of outgoing RPC replies from server
* See [RPC output not verified by yang](https://github.com/clicon/clixon/issues/283)
* This lead to some corrections of RPC replies in system code
This include plugin module init and exit functions
New type: clixon_plugin_t exposed via public API while struct clixon_plugin is private
- Makefile changes for static linkage using "LINKAGE=static"
- Moved nacm external init to later stage in backend_main
* Not backward compatible: All uses of the ca-auth callback in restconf plugins must be changed
* New version is: `int ca_auth(h, req, auth_type, authp, userp)`
* where `auth_type` is the requested authentication-type (none, client-cert or user-defined)
* `authp` is the returned authentication flag
* `userp` is the returned associated authenticated user
* and the return value is three-valued: -1: Error, 0: not handled, 1: OK
* For more info see [clixon-docs/restconf](https://clixon-docs.readthedocs.io/en/latest/restconf.html)
* Replaces the hardcoded "config" keyword.
* Implemented by a compile-time option called `DATASTORE_TOP_SYMBOL` option in clixon_custom.h
* Tests: added endtest to all tests. Removed all premature exits if BE=0
* Introduced a delay before making process start/stop/restart processes for race conditions when configuring eg restconf
* For restconf `CLICON_BACKEND_RESTCONF_PROCESS`, restart restconf if restconf is edited.
* Not backward compatible: All uses of the ca-auth callback in restconf plugins must be changed
* New version is: `int ca_auth(h, req, auth_type, authp, userp)`
* where `auth_type` is the requested authentication-type (none, client-cert or user-defined)
* `authp` is the returned authentication flag
* `userp` is the returned associated authenticated user
* and the return value is three-valued: -1: Error, 0: ignored, 1: OK
* For more info see [clixon-docs](https://clixon-docs.readthedocs.io/en/latest/restconf.html)
* New clixon-restconf@2020-12-30.yang revision
* New clixon-lib@2020-12-30.yang revision
* Added callback to process-control RPC feature in clixon-lib.yang to manage processes
* Changed behavior of starting restconf internally using `CLICON_BACKEND_RESTCONF_PROCESS` monitoring changes in enable flag, not only the RPC.
* Changed: RPC process-control output parameter status to pid
1. Added #ifdef extern "C" to public header files.
2. Changed variables that are key words in c++, to different names (like ns instead of namespace).
3. Changed char* to const char* for constant strings.
* In summary, a user registers an upgrade callback per module. The callback is called at startup if the module is added, has been removed or if the revision on file is different from the one in the system.
* The register function has removed `from` and `rev` parameters: `upgrade_callback_register(h, cb, namespace, arg)`
* The callback function has a new `op` parameter with possible values: `XML_FLAG_ADD`, `XML_FLAG_CHANGE` or `XML_FLAG_CHANGE`: `clicon_upgrade_cb(h, xn, ns, op, from, to, arg, cbret)`
* Added: stats RPC for clixon XML and memory statistics.
* Added: restart-plugin RPC for restarting individual plugins without restarting backend.
* xml-stats moved from clixon-config.yang as state data to an rpc `datastats` in clixon-lib.yang
* Experimental: restart_plugin
* Two new plugin callbacks added
* ca_daemon: Called just after a server has "daemonized", ie put in background.
* ca_trans_commit_done: Called when all plugin commits have been done.
* Note: If you have used "end" callback and usign transaction data, you should probably use this instead.
* Two new plugin callbacks added
* ca_daemon: Called just after a server has "daemonized", ie put in background.
* ca_trans_commit_done: Called when all plugin commits have been done.
