Change compression to 0-100, update docs.

There is a difference in file size between compression of 99 and 100. The current code sets an int of '9' to a compression of 99, and other ints to always end in a 9.

For example I have a generated file with these sizes:
compression level : file size
50: 133kb
89: 156kb
90: 118kb
99: 155kb
100: 118kb
119: 155kb

Frankly I have no idea why the compressor has much bigger files when you give it an option that ends in in '9'. But the current way the compression options are passed to the compression forces them to end in a 9.