Merge pull request #1908 in SNORT/snort3 from ~BBANTWAL/snort3:lua_whitelist to master

Merge pull request #1908 in SNORT/snort3 from ~BBANTWAL/snort3:lua_whitelist to master

Squashed commit of the following:

commit b3a7aed754ada79a9493d27b9eda4cac57db6810
Author: Bhagya Tholpady <bbantwal@cisco.com>
Date:   Tue Feb 11 20:54:48 2020 -0500

    doc: update documentation for lua whitelist

commit c91dc91110887f7348fe09f60b4fad2a95de4fe4
Author: Bhagya Tholpady <bbantwal@cisco.com>
Date:   Tue Feb 11 20:52:38 2020 -0500

    main: add verbose output and print whitelist during reload

commit 3c54fac801e3ea60854e34cd8d46dc0b8e27f64a
Author: Bhagya Tholpady <bbantwal@cisco.com>
Date:   Tue Feb 11 20:52:15 2020 -0500

    lua: update lua files to whitelist the tables defined.
    define default_whitelist and whitelist them in snort_defaults.lua
    file_magic.lua to add file_magic table to whitelist

commit a1867b791cd05bcf36e308f701423aee08ae8dd4
Author: Bhagya Tholpady <bbantwal@cisco.com>
Date:   Tue Feb 11 20:48:44 2020 -0500

    module_manager: add snort_whitelist_append and snort_whitelist_add_prefix ffis
    These ffis add table names and prefixes to the lua whitelist used to print warnings when modules for the table names are not found in snort.
    split bootstrap into two lua files( bootstrap and finalize )
    load aliases before called snort_traversal in finalize.lua
    main: move config_lua to Shell::configure
    snort: add new warn flag warn-conf-strict that will throw out warning when table is not found