This patch adjust cffi definitions and also all associated functions
based on libyang v4.

Closes: #160
Signed-off-by: Stefan Gula <steweg@gmail.com>
Signed-off-by: Jeremie Leska <jeremie.leska@6wind.com>
Signed-off-by: Samuel Gauthier <samuel.gauthier@6wind.com>

libyang returns the realtype field when the store callback return code
is LY_SUCCESS and LY_EINCOMPLETE.
Don't raise an error when lyd_value_validate_dflt returns
LY_EINCOMPLETE. The function can then use the val_type_cdata field.
Add a leafref with a default value to yolo-nodetypes.yang.
In this case, lyd_value_validate_dflt returns LY_EINCOMPLETE.
In test_schema.py, check that the default function returns a correct str
value.

Link: https://github.com/CESNET/libyang/blob/master/src/tree_data_common.c#L682
Signed-off-by: Jeremie Leska <jeremie.leska@6wind.com>

The sed command with the regex fails to keep the sha1 and remove the
commit title from the 'Fixes' trailer. Then the git command fails to
find the commit. A commit with 'Fixes' can not be validated by the
script.
Fix the regex to extract the sha1.

Signed-off-by: Jeremie Leska <jeremie.leska@6wind.com>

This log was introduced for debug. Remove it.

Fixes: 0a4b09f ("cffi: allows to usage of libyang v4")
Signed-off-by: Jeremie Leska <jeremie.leska@6wind.com>

It is not always possible to get the features from the parsed module.
It is the case for a module obtained from a sysrepo printed context.
Introduce compiled_enabled_features that returns the features from
the compiled object.

Signed-off-by: Jeremie Leska <jeremie.leska@6wind.com>

In libyang4, when dealing with printed contexts, cdata_parsed is not
set.
Check it before using it to get the node type.

Fixes: 0a4b09f ("cffi: allows to usage of libyang v4")
Signed-off-by: Jeremie Leska <jeremie.leska@6wind.com>