Implement SimpleBot native client (#86)

Cargo.lock

@@ -1053,6 +1053,7 @@ version = "0.0.1"
 dependencies = [
  "clap",
  "libremetaverse",
+ "tokio",
 ]
 
 [[package]]
@@ -1936,6 +1937,16 @@ version = "2.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f8fadd59c855ef2080decdef8ff161eb6661b86933c9d82e5ba29dc602a55aba"
 
+[[package]]
+name = "signal-hook-registry"
+version = "1.4.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c4db69cba1110affc0e9f7bcd48bbf87b3f4fc7c61fc9155afd4c469eb3d6c1b"
+dependencies = [
+ "errno",
+ "libc",
+]
+
 [[package]]
 name = "simd-adler32"
 version = "0.3.10"
@@ -2173,6 +2184,7 @@ dependencies = [
  "libc",
  "mio",
  "pin-project-lite",
+ "signal-hook-registry",
  "socket2",
  "tokio-macros",
  "windows-sys 0.61.2",