set text color for menus

fix cgeo#66

- remove theme definitions for api 11 an 14, merge them in the default configuration files (we are on min sdk 16)
- add text color definitions
- define the default text color (white) fo the AppTheme

src/main/res/values/colors.xml

@@ -19,4 +19,6 @@
     <color name="title_separator">#40ffffff</color>
     <color name="title_separator_dark">#40000000</color>
     <color name="btn_disabled">#80aaaaaa</color>
+    <color name="text_dark">#FFFFFFFF</color>
+    <color name="text_light">#FF000000</color>
 </resources>

src/main/res/values/styles_theme.xml

@@ -1,10 +1,10 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources xmlns:android="http://schemas.android.com/apk/res/android">
 
-    <style name="AppTheme" parent="@android:style/Theme.Light.NoTitleBar">
+    <style name="AppTheme" parent="@android:style/Theme.Holo.Light.NoActionBar">
         <item name="android:windowAnimationStyle">@null</item>
+        <item name="android:textColor">@color/text_dark</item>
     </style>
 
-    <style name="ThemeSettings" parent="android:Theme" />
-
-</resources>
+    <style name="ThemeSettings" parent="@android:style/Theme.Holo.Light.DarkActionBar" />
+</resources>

src/main/res/values/themes.xml

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
 
-    <style name="Mapsforge" parent="@android:style/Theme.NoTitleBar" />
+    <style name="Mapsforge" parent="@android:style/Theme.Holo" />
 </resources>