lib: improve error handling, cleanups

lib/utils/mu-error.hh

@@ -30,7 +30,7 @@ namespace Mu {
 struct Error final: public std::exception {
 
         enum struct Code {
-                AccessDenied,
+                AccessDenied = 100, // don't overlap with MuError
                 Command,
                 File,
                 Index,
@@ -127,7 +127,6 @@ struct Error final: public std::exception {
 private:
         const Code   code_;
         std::string  what_;
-
 };
 
 

lib/utils/mu-readline.hh

@@ -21,7 +21,7 @@
 namespace Mu {
 
 /**
- * Setup readline when available & on tty.
+ * Setup readline when available and on tty.
  *
  * @param histpath path to the history file
  * @param max_lines maximum number of history to save