Install libnghttp2-devel in ubuntu and centos per required dependencies
Ignore case when checking XML declaration encoding value per W3C recommendations
Fix filter logic to follow RFC6241 (7.1, 7.7) and default to subtree
* Hello message semantics has been made stricter according to RFC 6241 Sec 8.1, for example:
* A client MUST send a <hello> element.
* Each peer MUST send at least the base NETCONF capability, "urn:ietf:params:netconf:base:1.1" (or 1.0 for RFC 4741)
* The netconf client will terminate (close the socket) if the client does not comply
* You can set `CLICON_NETCONF_HELLO_OPTIONAL` to true to use the old behavior of essentially ignoring hellos.
* New clixon-config@2020-03-08.yang revision
* Added: `CLICON_NETCONF_HELLO_OPTIONAL`
* The base capability has been changed to "urn:ietf:params:netconf:base:1.1" following RFC6241.
* Reduced memory for attribute and body objects, see `XML_NEW_DIFFERENTIATE` compile-time option.
* Optimized cbuf handling in parsing and xml2cbuf functions.
* Optimized xml scanner to read strings rather than single chars
* Optimized xml_merge for the case of disjunct trees.
* If you have used, `ys`, add `xml_spec_set(x, ys)` after the statement
* If you have `xml_type_set(x, TYPE)` or `xml_prefix_set(x, PREFIX)` immediately after the statement, you can remove those and set them directly as: `xml_new(name, PREFIX, xp, TYPE)`
* empty values of yang type `empty` are encoded as: `{"x":[null]}`
* empty string values are encoded as: `{"x":""}` (changed from `null` in 4.0 and `[null]` in 4.3)
* empty containers are encoded as: `{"x":{}}`
* empty elements in unknown/anydata/anyxml encoded as: `{"x":{}}` (changed from `{"x":null}`)
w-level general upgrades and as a complement to module-specific upgrade.
* Called on startup after initial XML parsing, but before module-specific upgrades
* Enabled by definign the `.ca_datastore_upgrade`
* [General-purpose upgrade documentation](https://clixon-docs.readthedocs.io/en/latest/backend.html#ge
neral-purpose)
* JSON parse error messages change from ` on line x: syntax error,..` to `json_parse: line x: syntax err
or`
* Unknown-element error message is more descriptive, eg from `namespace is: urn:example:clixon` to: `Fai
led to find YANG spec of XML node: x with parent: xp in namespace urn:example:clixon`.
* C-API parse and validation API more capable
* `xml_spec_populate` family of functions extended with three-value return values
* -1: error, 0: parse OK, 1: parse and YANG binding OK.
* `xml_parse` and `json_parse` API changes
* Three value returns: -1: error, 0: parse OK, 1: parse and YANG binding OK.
* Extended `xml_parse_file2` and `xml_parse_string2` extended API functions with all options available.
* New concept called `yang_bind` that defines how XML symbols are bound to YANG after parsing
* Existing API same except `xml_parse_file` `endtag` argument moved to `xml_parse_file2`
* C-API: Added instrumentation: `xml_size` and `xml_stats_get`.
* Fixed: Enabling modstate (CLICON_XMLDB_MODSTATE), changing a revision on a yang, and restarting made the backend daemon exit at start (thanks Matt)
* Also: ensure to load `ietf-yang-library.yang ` if CLICON_XMLDB_MODSTATE is set
* For backward compatibility, load of startup and running set CLICON_XML_NS_STRICT to false temporarily.
* Added three-valued return values for several validate functions where -1 is fatal error, 0 is validation failed and 1 is validation OK.
* This includes: `xmldb_put`, `xml_yang_validate_all`, `xml_yang_validate_add`, `xml_yang_validate_rpc`, `api_path2xml`, `api_path2xpath`
* Added new xml functions for specific types: `xml_child_nr_notype`, `xml_child_nr_notype`, `xml_child_i_type`, `xml_find_type`.
* For Example, adding bad-, missing-, or unknown-element error messages, etc instead of operation-failed
* Removed delete-config support for candidate db since it is not supported in RFC6241.
* Switched the order of `error-type` and `error-tag` in all netconf and restconf error messages to comply to RFC order.
* Added example_rpc RPC to example backend
* Renamed xml_namespace[_set]() to xml_prefix[_set]()
* Some restconf error messages contained "rpc-reply" or "rpc-error" which have now been removed.
* Netconf/Restconf RPC extra input arguments are ignored (https://github.com/clicon/clixon/issues/47)
* `CLICON_YANG_DIR` is changed from a single directory to a path of directories
* Note CLIXON_DATADIR (=/usr/local/share/clixon) need to be in the list
* CLICON_YANG_MAIN_FILE Provides a filename with a single module filename.
* CLICON_YANG_MAIN_DIR Provides a directory where all yang modules should be loaded.
* Change all @datamodel:tree to @datamodel in all CLI specification files
* If you generate CLI code from the model (CLIXON_CLI_GENMODEL).
* For backward compatibility, define CLICON_CLI_MODEL_TREENAME_PATCH in clixon_custom.h
* Removed return value ymodp from yang parse functions (eg yang_parse()).
* New config option: CLICON_CLI_MODEL_TREENAME defining name of generated syntax tree if CLIXON_CLI_GENMODEL is set.
* Names lexically correct (NCName)
* Syntactically Correct handling of '<?' (processing instructions) and '<?xml' (XML declaration)
* XML prolog syntax for 'well-formed' XML
* <!DOCTYPE (ie DTD) is not supported.
