Add support for parsing Collections and Maps from the Spring YML format

[akang31]

Add support for understanding the Spring YML (YamlPropertiesFactoryBean) way of parsing YML files via the Archaius endpoints. This supports the ConfigProxy and PropertyRepository as these all are eventually backed by AbstractConfig.

This enables all existing Archaius read methods to read multi-line/multi-property maps and arrays as specified by Spring.

Spring YML files are converted to configs from this yml file

test:
    map:
        key1: 1
        key2: 2
        key3: 3
    stringList:
        - a
        - b
        - c

To these configs:

test.map.key1=1
test.map.key2=2
test.map.key3=3
test.stringList[0]=a
test.stringList[1]=b
test.stringList[2]=c

[rgallardo-netflix]

Maybe move these two to be private static helper methods in AbstractConfig? Then things would work with any ParametrizedType, not just with ArchaiusType.

[rgallardo-netflix]

I don't ... hate this, but let's think about it a bit more. I'd really love it if there was some way we could call the existing decoders here instead of marshaling the entire map into a single string just to unmarshal it back a nanosecond later. The same goes for the List support.