osx: Tweak colors of command line args box.

In a previous change (I think d8cfdba5bf ?) I changed the text
entry box for command line arguments to be white on a black
background, with the idea being that it was more similar to a DOS
window. @Linguica reports that this doesn't look nice on Macs which
have low-res displays, so revert back to default colors, and also
change the font to use the system font for user-selected fixed
width. I believe this fixes #858.

pkg/osx/Resources/launcher.nib/designable.nib

@@ -1,8 +1,9 @@
-<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<?xml version="1.0" encoding="UTF-8"?>
-<document type="com.apple.InterfaceBuilder3.Cocoa.XIB" version="3.0" toolsVersion="9532" systemVersion="15F34" targetRuntime="MacOSX.Cocoa" propertyAccessControl="none">
+<document type="com.apple.InterfaceBuilder3.Cocoa.XIB" version="3.0" toolsVersion="11762" systemVersion="16D32" targetRuntime="MacOSX.Cocoa" propertyAccessControl="none">
     <dependencies>
         <deployment version="1070" identifier="macosx"/>
-        <plugIn identifier="com.apple.InterfaceBuilder.CocoaPlugin" version="9532"/>
+        <plugIn identifier="com.apple.InterfaceBuilder.CocoaPlugin" version="11762"/>
+        <capability name="documents saved in the Xcode 8 format" minToolsVersion="8.0"/>
     </dependencies>
     <objects>
         <customObject id="-2" userLabel="File's Owner" customClass="NSApplication">
@@ -51,8 +52,8 @@
                         <autoresizingMask key="autoresizingMask"/>
                         <imageCell key="cell" refusesFirstResponder="YES" alignment="left" animates="YES" imageScaling="axesIndependently" image="128x128" id="327"/>
                     </imageView>
-                    <textField verticalHuggingPriority="750" id="218">
+                    <textField verticalHuggingPriority="750" misplaced="YES" id="218">
-                        <rect key="frame" x="18" y="125" width="360" height="11"/>
+                        <rect key="frame" x="18" y="125" width="350" height="11"/>
                         <autoresizingMask key="autoresizingMask"/>
                         <textFieldCell key="cell" sendsActionOnEndEditing="YES" id="329">
                             <font key="font" metaFont="miniSystem"/>
@@ -66,9 +67,9 @@
                         <rect key="frame" x="20" y="49" width="346" height="68"/>
                         <autoresizingMask key="autoresizingMask"/>
                         <textFieldCell key="cell" selectable="YES" editable="YES" sendsActionOnEndEditing="YES" state="on" borderStyle="border" drawsBackground="YES" id="330">
-                            <font key="font" size="11" name="CourierNewPSMT"/>
+                            <font key="font" metaFont="fixedUser" size="11"/>
-                            <color key="textColor" red="1" green="1" blue="1" alpha="1" colorSpace="calibratedRGB"/>
+                            <color key="textColor" name="textColor" catalog="System" colorSpace="catalog"/>
-                            <color key="backgroundColor" red="0.29793848167539272" green="0.29793848167539272" blue="0.29793848167539272" alpha="1" colorSpace="calibratedRGB"/>
+                            <color key="backgroundColor" name="textBackgroundColor" catalog="System" colorSpace="catalog"/>
                         </textFieldCell>
                     </textField>
                     <button horizontalHuggingPriority="750" verticalHuggingPriority="750" id="5zZ-CS-NR1">