* Fixed multi-namespace for augmented state which was not covered in 4.2.0.
* The multi-namespace augment state may rearrange the XML namespace attributes.
* Mandatory variables can no longer be deleted.
RFC 8040 Sec 3.1
* non-pretty print remove all spaces, eg `{"operations":{"clixon-example:client-rpc":[null]`
* Replaced JSON `null` with `[null]` as proper empty JSON leaf/leaf-list encoding.
* [Cannot write to config using restconf example #91](https://github.com/clicon/clixon/issues/91)
* Updated restconf documentation (the example was wrong)
* [clixon-lib yang revision file name update #92](https://github.com/clicon/clixon/issues/92)
* Clixon-lib yang file had conflicting filename and internal yang revision.
* This was only detected in the use-case when a whole dir was loaded.
* Inserted sanity check in all yang parse routines.
* Committed updated clixon-lib yang file that triggered the error
* New clixon-lib@2019-08-13.yang revision
* Bugfix: If `ietf-netconf.yang` was imported from any yang module, client/backend communication stops working.
* Restconf RFC 8040 increased feature compliance
* Cache-Control: no-cache added in HTTP responses (RFC Section 5.5)
* Restconf monitoring capabilities (RFC Section 9.1)
* Added support for Yang extensions
* New plugin callback: ca_extension
* Main backend example includes example code on how to implement a Yang extension in a plugin.
* JSON changes
* Non-pretty-print output removed all extra spaces.
* Example: `{"nacm-example:x": 42}` --> {"nacm-example:x":42}`
* Empty JSON container changed from `null` to `{}`.
* Empty list and leafs remain as `null`
* Removed unnecessary configure dependencies
* libnsl, libcrypt, libm, if_vlan,...
* pseudo-plugin added, to enable callbacks also for main programs. Useful for extensions
* Yang Unique statements with multiple schema identifiers did not work on some platforms due to memory error.
The reason is to be conservative with the API. However, less used functions, such as xpath_vec_bool(), xpath_vec_ctx() and xpath_vec_flag() are changed with a new `nsc`parameter, which should be set to NULL in most cases.
* Added check for libxml in configure';
* Added clixon_util_regexp utility function
* Yang state get improvements
* Integrated state and config into same tree on retrieval, not separate trees
* Added cli functions `cli_show_config_state()` and `cli_show_auto_state()` for showing combined config and state info.
* Added integrated state in the main example: `interface/oper-state`.
* Added performance tests for getting state, see [test/test_perf_state.sh].
* Validate-only transactions are terminated by an `end` or `abort` callback.
* If a commit user callback fails, a new `revert` callback will be made to plugins that have made a succesful commit.
* See [Restconf does not handle startup datastore according to the RFC](https://github.com/clicon/clixon/issues/74)
* Netconf Startup feature is no longer hardcoded, you need to explicitly enable it (See RFC 6241, Section 8.7)
* Enable in config file with: `<CLICON_FEATURE>ietf-netconf:startup</CLICON_FEATURE>`, or use `*:*`
* Change all y->ys_parent to yang_parent_get(y)
* Change all y->ys_keyword to yang_keyword_get(y)
* Change all y->ys_argument to yang_argument_get(y)
* Change all y->ys_cv to yang_cv_get(y)
* Change all y->ys_cvec to yang_cvec_get(y)
* also renamed `xml_insert` to `xml_wrap_all`.
* Added `clicon_argv_get()` function to get the user command-line options, ie the args in `-- <args>`. This is an alternative to using them passed to `plugin_start()`.
* Start with `-- -r` to run the reset plugin
* Start with `-- -s` to run the state callback
* Rewrote yang dir load algorithm to follow the algorithm in [FAQ](FAQ(doc/FAQ.md#how-are-yang-files-found) with more precise timestamp checks, etc.
* Extra RPC:s will be called _after_ the basic ones.
* One specific usecase is hook for `copy-config` (see [doc/ROADMAP.md] that can be implemented thus way.
* `rpc_callback_register` added a namespace parameter. Example:
```
rpc_callback_register(h, empty_rpc, NULL, "urn:example:clixon", "empty");
```
* clixon-config YAML file has new revision: 2019-03-05.
* New URN and changed top-level symbol to `clixon-config`
* Removed obsolete `_CLICON_XML_NS_STRICT` variable and `CLICON_XML_NS_STRICT` config option.
