adds support for numpad Enter key on macos, differentiates between return/enter keys, and removes duplicate lines closes #167 (#168)

Author: smithkyle

src/keycode.h

@@ -80,6 +80,7 @@ enum _MMKeyCode {
 	K_DIVIDE = kVK_ANSI_KeypadDivide,
 	K_MULTIPLY  = kVK_ANSI_KeypadMultiply,
 	K_CLEAR = kVK_ANSI_KeypadClear,
+	K_ENTER = kVK_ANSI_KeypadEnter,
 
 	K_NUMPAD_0 = kVK_ANSI_Keypad0,
 	K_NUMPAD_1 = kVK_ANSI_Keypad1,
@@ -185,6 +186,7 @@ enum _MMKeyCode {
 	K_DIVIDE = XK_KP_Divide,
 	K_MULTIPLY  = XK_KP_Multiply,
 	K_CLEAR = XK_Clear,
+	K_ENTER = XK_Return,
 
 	K_NUMPAD_0 = XK_KP_0,
 	K_NUMPAD_1 = XK_KP_1,
@@ -287,6 +289,7 @@ enum _MMKeyCode {
 	K_DIVIDE = VK_DIVIDE,
 	K_MULTIPLY  = VK_MULTIPLY,
 	K_CLEAR = VK_CLEAR,
+	K_ENTER = VK_RETURN,
 
 	K_NUMPAD_0 = VK_NUMPAD0,
 	K_NUMPAD_1 = VK_NUMPAD1,

src/main.cc

@@ -220,7 +220,7 @@ static KeyNames key_names[] =
         {
                 {"backspace",         K_BACKSPACE},
                 {"delete",            K_DELETE},
-                {"enter",             K_RETURN},
+                {"return",            K_RETURN},
                 {"tab",               K_TAB},
                 {"escape",            K_ESCAPE},
                 {"up",                K_UP},
@@ -306,12 +306,7 @@ static KeyNames key_names[] =
                 {"multiply",          K_MULTIPLY},
                 {"divide",            K_DIVIDE},
                 {"clear",             K_CLEAR},
-
-                {"add",               K_ADD},
-                {"subtract",          K_SUBTRACT},
-                {"multiply",          K_MULTIPLY},
-                {"divide",            K_DIVIDE},
-                {"clear",             K_CLEAR},
+                {"enter",             K_ENTER},
 
                 {"lights_mon_up",     K_LIGHTS_MON_UP},
                 {"lights_mon_down",   K_LIGHTS_MON_DOWN},