Fix syntax of macro_rules for former #defines
Use closure in tinfl_decompress

Also expand comment in tinfl_decompressto cover more goto spaghetti.
This is the hardest part to translate, since it that type of control
flow is absent in Rust, so tinfl_decompress will probably be the last
function translated.
Rustify tinfl_decompress_mem_to_heap with Option & Vec
Rustify tinfl_decompress_mem_to_mem with Option & slice