* Made NETCONF message handling more strict according to RFC 6241
* Set `CLICON_NETCONF_MESSAGE_ID_OPTIONAL` to true to accept omission of message-id attribute
* Fixed: [need make sure message-id exist in rpc validate #240](https://github.com/clicon/clixon/issues/240)
- Fix event exit bug (set to new counter, dont increment)
- Changed default CI to be restconf=native instead of fcgi1~
- Tests:
- Change to same wait backend and restconf commands
- Change default restconf protocol from http to https
While porting clixon to the RTOS Blackberry QNX there was memory corruption while reading the yang models from the disk.
Debugging led to the function `clicon_file_dirent` in `clixon_file.c` in which the `struct dirent` is copied into an array.
According to the UNIX `struct dirent` [documentation](https://man7.org/linux/man-pages/man0/dirent.h.0p.html):
> The name of an array of char of an unspecified size should not be
> used as an lvalue. Use of:
>
> sizeof(d_name)
>
> is incorrect; use:
>
> strlen(d_name)
>
> instead.
I adjusted the memory allocation to take the `strlen(dent->d_name)` into account.
- Added autoconf config options, temporary for nghttp2 development: `--disable-evhtp`and `--enable-nghttp2`.
- Added special case for api-path:s beginning with //
* clixon_restconf daemon is installed in /usr/local/sbin (as clixon_backend), instead of /www-data
* `configure --with-wwwdir=<dir>` remains but only applies to fcgi socket and log
* New option `CLICON_RESTCONF_INSTALL_DIR` is set to where clixon_restconf is installed, with default `/usr/local/sbin/`
* Restconf drop privileges user is defined by `CLICON_RESTCONF_USER`
* `configure --with-wwwuser=<user>` is removed
* clixon_restconf drop of privileges is defined by `CLICON_RESTCONF_PRIVILEGES` option
* New clixon-restconf@2020-05-20.yang revision
* Added: restconf `log-destination`
* Several cases were not implemented fully according to RFC 7950
* Do not extend default values if when statements evaluate to false
* Do not allow edit-config of nodes if when statements evaluate to false (Sec 8.3.2)
* If a key leaf is defined in a grouping that is used in a list, the "uses" statement MUST NOT have a "when" statement. (See 7.21.5)
* See [yang uses's substatement when has no effect #218](https://github.com/clicon/clixon/issues/2$
* Example: `GET restconf/data/x:a=`
* Previous meaning (wrong): Return all `a` elements.
* New meaning (correct): Return the `a` instance with empty key string: "".
* [RESTCONF GET request of single-key list with empty string returns all elements #213](https://github.com/clicon/clixon/issues/213)
* [RESTCONF GETof lists with empty string keys does not work #214](https://github.com/clicon/clixon/issues/214)
