**Problem**
1. Currently users are automatically opted into -create-sbt,
somewhat implicitly.
2. When somehow they are not, the check mechanism currently blocks for input.
**Solution**
1. Support a new location for sbtopts file under XSG_CONFIG_HOME/sbt
2. Rename -create-sbt to --allow-empty, and don't opt everyone in
3. Exit 1 instead of blocking for input
Fixes#7387
* Fix VM argument passing by .sbtopts file and JAVA_TOOL_OPTIONS environmental variable, improve launcher script integration test setup
* Fix sbt process not exiting in launcher test for --sbt-version
* Fix JAVA_TOOL_OPTIONS in launcher for linux/mac
Eugene Yokota
Domantas Petrauskas
Eric Peters