Add '--propertyFile' command-line parameter, to override where SQLLine reads its configuration

[julianhyde]

Add --propertyFile command-line parameter, to override where SQLLine reads its configuration.

Note that https://issues.apache.org/jira/browse/HIVE-13964 is a similar feature in Hive (except that the option is called --property-file).

We should support (and test) --propertyFile=/dev/null.

Also, if this option is given, we should not attempt to write the properties back.

[julianhyde]

As part of this change, in our script tests, we should use --propertyFile=/dev/null (or an API-level equivalent), and remove various !set commands at the start of those tests, some of which we added as a workaround in #237.

[snuyanzin]

I noticed existing but not working as expected property propertiesFile and started to use this one

[snuyanzin]

Merged as 81434e4