Update to the STATS TEXTANALYSIS extension command

[jkpeck]

I have updated the STATS TEXTANALYSIS extension command to version 1.2.0.  The changes are
- simplified installation instructions
- ability to create datasets of negative terms and emphasis terms as well as the dataset of terms and scores for sentiment analysis
- ability to add or modify all three types of terms and their scores.

The latest version is available on the Extension Hub, as usual.