Uncompressed frame buffer pool

[ruccho]

Closes #57

• Adds SharedBufferPool, which is a frame buffer pool for uncompressed frames shared between C# and Rust.
  • Frame buffers are allocated from C# world and passed to unienc without copies, and its lifetime is migrated to Rust world.
  • SharedBufferPool has a limit of total size of buffers. Frames will be dropped when there is no space to allocate new buffers.
  • It helps us to reduce runtime memory allocations.
• Adds ILogger to make it possible to redirect all logs from Instant Replay.
• Sets unienc panicking behavior to abort, making stacktraces easier to analyze.
  • With default configuration unwind, crash report will contain a stacktrace of Rust's panic handler and it doesn't let us know cause of the panic (details are wrote to stderr), but with abort, the stacktrace will contain exact callers of panicking code.