ignore the static linking file of lz4...
The flag should contain more info. The encryption method / compress shouldn't set by config.json in server side.
using a fixed block size for compression
using fixed buffer size from compression unit.
merge 4 fixme in to one.
Revert "The flag should contain more info. The encryption method / compress shouldn't set by config.json in server side."

This reverts commit 6eabee1d47db499eae785bb81599779bbbfe0cc6.