iOS: fix warning for iOS7

contrib/mobile/Trackball.cpp

@@ -221,7 +221,7 @@ void axis_to_quat(double a[3], double phi, double q[4])
 static double
 tb_project_to_sphere(double r, double x, double y)
 {
-  double d, t, z;
+  double d, z;
 
   d = sqrt(x*x + y*y);
 

contrib/mobile/iOS/Onelab/ModelViewController.mm

@@ -369,7 +369,7 @@ void getBitmap(void *self, const char *text, int textsize, unsigned char **map,
     lbl.font = [UIFont systemFontOfSize:textsize];
     [lbl setText:[NSString stringWithCString:text  encoding:[NSString defaultCStringEncoding]]];
     [lbl setBackgroundColor:[UIColor clearColor]];
-    CGSize lblSize = [[lbl text] sizeWithFont:[lbl font]];
+    CGSize lblSize = [[lbl text] sizeWithAttributes:@{NSFontAttributeName:[lbl font]}];
     *realWidth = lblSize.width;
     int i;
     for(i=2;i<*realWidth;i*=2); *width = i;

contrib/mobile/iOS/Onelab/OptionsViewController.mm

@@ -43,7 +43,6 @@
 
     [self.navigationController setToolbarHidden:NO];
 	control = [[UISegmentedControl alloc] initWithItems:[[NSArray alloc] initWithObjects:@"Model", @"Display", nil]];
-	control.segmentedControlStyle = UISegmentedControlStyleBar;
 	UIBarButtonItem *controlBtn = [[UIBarButtonItem alloc] initWithCustomView:control];
 	UIBarButtonItem *flexibleSpace = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFlexibleSpace target:nil action:nil];
 	self.toolbarItems = [[NSArray alloc] initWithObjects:flexibleSpace, controlBtn, flexibleSpace, nil];