Pharo XML support packages moved to GitHub

In November 2019 some time was spend to move the XML Support for Pharo from old SmalltalkHub to a community managed location on GitHub:

     https://github.com/pharo-contributions

For the detailed packages this means

• BitmapCharacterSet moved to GitHub
• XMLWriter moved to GitHub
• OrderPreservingDictionary was updated to 1.5.0
• XMLParser moved to GitHub
• XMLParserHTML moved to GitHub
• XMLParserStAX moved to GitHub
• XPath moved to GitHub
• Pastell moved to GitHub

Fortunately there is a nice tool from Peter Uhnak called "git-migration" that helped a lot in this transition and preserved original commit history as much as possible. 

Additionally some more cleanups were applied and a continuous integration (CI) was established.

The move to GitHub should help to better maintain contributions to these projects and also verify that the XML support runs on newer Pharo versions.