Remove path-separator, since the name is confusing. (#67)

You can use LIST-SEPARATOR from the fs package.

Also adds missing types on flags.

Author: Erik Corry

src/file.toit

@@ -269,14 +269,14 @@ rename from/string to/string -> none:
 /**
 Creates a hard link from $source to a $target file.
 */
-link --hard --source/string --target/string -> none:
+link --hard/bool --source/string --target/string -> none:
   if not hard: throw "INVALID_ARGUMENT"
   link_ source target LINK_TYPE_HARD_
 
 /**
 Creates a soft link from $source to a $target file.
 */
-link --file --source/string --target/string -> none:
+link --file/bool --source/string --target/string -> none:
   if not file: throw "INVALID_ARGUMENT"
   if is-directory target:
     throw "Target is a directory"
@@ -285,7 +285,7 @@ link --file --source/string --target/string -> none:
 /**
 Creates a soft link from $source to a $target directory.
 */
-link --directory --source/string --target/string -> none:
+link --directory/bool --source/string --target/string -> none:
   if not directory: throw "INVALID_ARGUMENT"
   if is-file target:
     throw "Target is a file"

src/os.toit

@@ -58,16 +58,6 @@ A map-like object that represents the environment variables of the current
 */
 env / EnvironmentVariableMap ::= EnvironmentVariableMap.private_
 
-/**
-The path separator for the underlying operating system.
-*/
-path-separator -> string:
-  if system.platform == system.PLATFORM-FREERTOS: throw "UNSUPPORTED"
-  if system.platform == system.PLATFORM-WINDOWS:
-    return ";"
-  else:
-    return ":"
-
 get_env_ key/string -> string?:
   #primitive.core.get_env