Disabling autocomplete in string and comment contexts

Fix for MAGN-5099: http://adsk-oss.myjetbrains.com/youtrack/issue/MAGN-5099

This refers to issue: https://github.com/DynamoDS/Dynamo/issues/2942

@Benglin please review
@ke-yu could you elaborate on this? I didn't get the inconsistent naming bit.