- Package extensions in a separate package - libyang-extentions

- Update to version 1.0r5
Main features of this release are:
* value canonization support in API functions
* new debug message categories
* nested notification/action validation clarifications and fixes
* LYB format decimal64 value handling fixed
* C++ bindings minor improvements
* other minor fixes

- Update to version 1.0r4
Main features of this release are:
* many bugfixes in various parts of the library
+ schema and data validation
+ manipulation with internal schemas and loading user schemas
in the context
+ xpath
+ LYB format

- Update to version 1.0r3
Main features of this release are:
* many bugfixes in various parts of the library
+ LYB format
+ schema
+ data
+ xpath

- Build with ENABLE_LYD_PRIV=ON