Fixed compilation errors and warnings with GCC 4.7

Also, since GCC 4.7 there is a binary compatibility issue when linking with a
Guichan that was not compiled in C++11 mode. This commit also allows compiling
with GCC 4.7 with C++11 mode turned off.

Reviewed-by: Erik Schilling

src/cpp0x_compat/cstdint

@@ -1,7 +1,10 @@
 /*
  * Compatibility header used when the compiler doesn't support C++0x.
  *
- * It doesn't seem necessary for it to contain anything, at least GCC 4.2.1
- * compiles Mana fine so it apparently understands types like uint16_t by
- * default.
+ * While GCC 4.2.1 understands types like uint16_t by default, later versions
+ * are more strict so here are some typedefs for types used in our code.
  */
+
+typedef unsigned char  uint8_t;
+typedef unsigned short uint16_t;
+typedef unsigned int   uint32_t;

src/gui/widgets/tabbedarea.h

@@ -98,7 +98,8 @@ class TabbedArea : public gcn::TabbedArea, public gcn::WidgetListener
         int getContainerHeight() const
         { return mWidgetContainer->getHeight(); }
 
-        using gcn::TabbedArea::setSelectedTab;
+        void setSelectedTab(unsigned int index)
+        { gcn::TabbedArea::setSelectedTab(index); }
 
         void setSelectedTab(gcn::Tab *tab);
 

src/gui/widgets/textfield.h

@@ -63,6 +63,7 @@ struct TextHistory {
 
 class AutoCompleteLister {
 public:
+    virtual ~AutoCompleteLister() {}
     virtual void getAutoCompleteList(std::vector<std::string>&) const {}
 };
 

src/net/download.h

@@ -18,6 +18,7 @@
  *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include <cstdlib> // pulls in int64_t
 #include <cstdio>
 #include <string>
 

src/resources/itemdb.h

@@ -78,7 +78,7 @@ class ItemDB
           mLoaded(false)
         {}
 
-        ~ItemDB()
+        virtual ~ItemDB()
         {}
 
         /**