* Added regex cache to type resolution * Added compiled regexp parameter as part of internal yang type resolution functions * All internal `ys_populate_*()` functions (except ys_populate()) have switched parameters: `clicon_handle, yang_stmt *)`
* Added libxml2 XSD regexp mode as alternative to posix translation * Added `CLICON_YANG_REGEXP` option with possible values libxml2 and posix
* Added `\p{L}` and `\p{N}` * Added escaping of `$` * Added regexp [test/test_pattern.sh]
