- npm install less@2.7 less-plugin-clean-css grunt-cli is moved inside manage.sh
- if it is possible to source manage.sh to update the PATH (to start grunt)
- tidy the help documentation
- update the geckodriver version to 0.19.1

- prevent whitespace-splitting of variable expansions
- prevent interpretation of values as flags/options

(mostly)

Fix issue #887, #962

Otherwise the script fails with spaces or asterisks in the directory path.