New code for codebook caching.

src/main/java/azgracompress/cache/CacheFileHeader.java

src/main/java/azgracompress/cache/ICacheFile.java

...in/java/azgracompress/cache/QuantizationCacheManager.java

src/main/java/azgracompress/cache/SQCacheFile.java

src/main/java/azgracompress/cache/VQCacheFile.java

...va/azgracompress/quantization/QuantizationValueCache.java