ksud: refine su and make it compitable with MagiskSU

Supported features:

1.  --mount-master, -M, -mm which would make the command run in global mount namespace.
2. - user to switch a specific user's shell.
3. -v, -V to print version code and name.

fix #330 #306 #305 #32

userspace/ksud/Cargo.lock

@@ -584,6 +584,15 @@ dependencies = [
  "version_check",
 ]
 
+[[package]]
+name = "getopts"
+version = "0.2.21"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "14dbbfd5c71d70241ecf9e6f13737f7b5ce823821063188d7e46c41d371eebd5"
+dependencies = [
+ "unicode-width",
+]
+
 [[package]]
 name = "getrandom"
 version = "0.2.8"
@@ -793,6 +802,7 @@ dependencies = [
  "encoding",
  "env_logger",
  "extattr",
+ "getopts",
  "humansize",
  "is_executable",
  "java-properties",