* import libunicode and libregexp from QuickJS
* add utility functions:
min/max_uint32, min/max_int64 clz/ctz/32/64
bswap12/32/64
* add packed get and put inline functions
* add DynBuf package (dbuf_xxx)
* add unicode_to/from_utf8()
* add regex support in eb_search
* add partial regex support in query_replace: no subexpressions support
* bumped VERSION to 6.1.0