* New clixon-lib@2019-08-13.yang revision
* Bugfix: If `ietf-netconf.yang` was imported from any yang module, client/backend communication stops working.
* Yang Netconf leaf/leaf-list insert support
* For "ordered-by user" leafs and leaf-lists, the insert and value/key attributes are supported according to RFC7950 Sections 7.7.9 and 7.8.6
* Fixed RESTCONF api-path leaf-list selection was not made properly
* `201 Created` for created resources
* `204 No Content` for replaced resources.
* See [RESTCONF: HTTP return codes are not according to RFC 8040](https://github.com/clicon/clixon/issues/56)
* HTTP `Location:` fields added in RESTCONF POST replies
* 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.
* Accepted:
```
curl -X PUT http://localhost/restconf/data/mod:a -d {"mod:a":"x"}
```
* Not accepted (must prefix "a" with module):
```
curl -X PUT http://localhost/restconf/data/mod:a -d {"a":"x"}
```
* Undefine `RESTCONF_NS_DATA_CHECK` in include/clixon_custom.h to disable strict check.
* 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)
* 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");
```
* Added clicon_socket_set() and clicon_socket_get() functions for cleaning up backend server and restconf FCGI socket on termination.
* Removed obsolete `-x` command-line option to clixon_cli.
* Moved datastore/text/ code to datastore/ since there is only one type of datastore.
* Added "magic script line" to test script for sourced and scriped exits
* Access control points added for `get` and `get-config` in addition to incoming rpc.
* RFC 8341 Example A.2 implemented, see: [test/test_nacm_module.sh]
* Added `username` argument on `xmldb_put()` datastore function for NACM data-node write checks
* Added `xml_rootchild_node()` lib function as variant of `xml_rootchild()`
