Rustify tinfl_decompress_mem_to_callback with slice & tuple
Make decompress functions public, use Rust types for constants
Clear slice with set_memory
fix macro invocations
casting syntax & closure fixes
Use u8 pointer instead of void pointers
Clear object with iterator
Partially rustify tdefl_compress_mem_to_output
Minor syntax fix, and macro replacement
For now, use ptr::null for null pointers

This is until we can replace these with Options