SPARK-3337 Paranoid quoting in shell to allow install dirs with spaces within.

...

Tested ! TBH, it isn't a great idea to have directory with spaces within. Because emacs doesn't like it then hadoop doesn't like it. and so on...
Do we want to put quotes around the whole thing as well?
```
export SPARK_TOOLS_JAR="`cygpath -w "$SPARK_TOOLS_JAR"`"
```