DRILL-6068: Support user/distrib-specific config checks during startup 1. Allows for distrib/user specific checks to be done 2. Place-holder files for distribution and user specific checks 3. Moved JVM Version Check to head of script Separation of setups into 3 levels
1. Apache Drill (Default) 2. Distribition Specific 3. User-Defined 1 & 2 are mutually exclusive. 3 is additional checks that the user can specify.