Move exceptions to its new package.

...main/java/azgracompress/compression/IImageCompressor.java

...in/java/azgracompress/compression/IImageDecompressor.java

src/main/java/azgracompress/compression/ImageCompressor.java

...ain/java/azgracompress/compression/ImageDecompressor.java

...ain/java/azgracompress/compression/SQImageCompressor.java

...n/java/azgracompress/compression/SQImageDecompressor.java

...ain/java/azgracompress/compression/VQImageCompressor.java

...n/java/azgracompress/compression/VQImageDecompressor.java

...ress/compression/exception/ImageCompressionException.java

...ss/compression/exception/ImageDecompressionException.java