[FL-1475] iButton emulate shortcat (#535)

* ibutton: run emulation when launched with argument
* app-loader: set NULL context when starting application from menu
* ibutton: change p to argc
* ibutton: fix load key data from file
* ibutton: fix memory leak

applications/ibutton/ibutton-app.h

@@ -39,7 +39,7 @@
 
 class iButtonApp {
 public:
-    void run(void);
+    void run(void* args);
 
     iButtonApp();
     ~iButtonApp();
@@ -100,6 +100,7 @@ public:
 
     bool save_key(const char* key_name);
     bool load_key();
+    bool load_key(const char* key_name);
     bool delete_key();
 
 private:
@@ -146,4 +147,5 @@ private:
     static const char* app_extension;
 
     void show_file_error_message(const char* error_text);
+    bool load_key_data(string_t key_path);
 };