* refactored logging in d2config, d2record, and d2asset
* asset manager, record manager, and file loader now utilitize d2util.Logger
* added colored logging to d2util.Logger (excluding windows platforms)
* removed mpq file verification from d2config; d2loader handles this
* record loaders now use the record manager's logger for printing info
* added command line argument for setting log level (`--loglevel 4`, `-l4`, or `-l 4`
* added `LogLevel` parameter to config file
* default log level will show errors, warnings, and info log messages
* specifying log level as an argument overrides setting from config file
* fixed log level tests
* removed dupl lint errors in d2compression/huffman.go
* remove duplicate code for set/unique item properties
This is a more involved edit. I've added a `PropertyDescriptor`
which is a common struct that should have existed already. The
`PropertyDescriptor` is used to generate property instances, and is common
to item affixes, set items, sets, unique items, and runewords.
This was all to remove duplicate code in d2item/
* removed duplicate code for rare item affixes
