Libyang

Main features of this release are:
- LYB format pathological meta data case fix
- caused data corruption
- new `lyd_validate()` flag `LYD_OPT_VAL_DIFF`
- causes validation to output the data node changes it made
- new `lyd_validate_modules()` function
- allows validating data of specified modules instead of the whole context
- greatly improved efficiency of `lyd_free_withsiblings()` and `lyd_dup_withsiblings()`
- false `when` autodelete behavior fixes
- new `yanglint` `load` command
- new make `uninstall` target
- support for GCC version `4.8.4` and lower
- many other small improvements and bugfixes

Main features of this release are:
- both little and big endianity support for LYB
- auto-delete `when` corrections
- minor bugfixes

Main features of this release are:
- new libyang proprietary binary format LYB
- JSON parser order fixes
- proper list `unique` validation
- new context dictionary implementation
- major C++ bindings improvements
- proprietary JSON schema printer
- many other smaller enhancements and bugfixes

Main features of this release are:
- data cache compilation option `ENABLE_CACHE` enabled by default
- data trees require ~20% more memory
- operations on these trees are much faster (depends on their size, on 20k nodes around 100-times faster)
- internal `ietf-yang-library` model updated
- new schema printer format `tree-rfc`
- extension validation callback
- error handling overhaul (more in DOCs)
- `yang-data` extension support
- support for user type plugins
- that can perform additional validation or custom value storing
- `json` data printer fixes so that it should be equal to `xml`
- static build support
- loads of minor or major bugfixes and enhancements

Main features of this release are:
- XPath evaluation optimized
- C++ bindings updated
- new function `ly_path_data2schema()` for transforming data paths to schema paths
- large number of bugfixes and minor enhancements

There are no API/ABI differences with the previous release.

Main features of this release are:
- large number of bugfixes
- mostly corner cases and complex YANG statement bugs