This release contains a major rewrite of the "Stringsext"
string-extraction-tool with the following improvements and new features:

* Much faster (>30%).
* Improved Unicode-Block-Filter:
  - Search in scripts with predefined filters e.g.
    *Latin*, *Arabic*, *Syriac*, *Cyrillic*, etc and any combination of
    these.
  - Configurable custom filter.
* Improved ASCII-Filter:
  - Predefined filters e.g. *all ASCII without controls* or *all
    ASCII with white-space, without controls".
  - Custom filters with configurable sets of ASCII-codes that
    pass the filter.
* New internal "grep"-like filter, mainly useful to search paths strings.
* More detailed position indication for long strings.
* Better interface with other stream oriented tools e.g. "head",
  "tail", "sed" and "grep".
* Better handling of zero terminated (C-style) strings in large fields.
* New backend "encoding_rs".

Changes in v2.1.0

* ASCII-filter `None` also suppresses the Null character (0x00).