Customization

Allows for changing border color, button controls

``` objc
        imgCropperVC.borderColor = [UIColor redColor];
        
        UIButton *confirmBtn = [[UIButton alloc] initWithFrame:CGRectMake(10, 40, 100, 40)];
        confirmBtn.layer.cornerRadius = 2;
        confirmBtn.layer.borderColor = [UIColor redColor].CGColor;
        confirmBtn.layer.borderWidth = 1;
        confirmBtn.backgroundColor = [UIColor whiteColor];
        [confirmBtn setTitleColor:[UIColor redColor] forState:UIControlStateNormal];
        [confirmBtn setTitle:@"Crop" forState:UIControlStateNormal];
        imgCropperVC.confirmBtn = confirmBtn;
        
        UIButton *cancelBtn = [[UIButton alloc] initWithFrame:CGRectMake(10, 90, 100, 40)];
        cancelBtn.layer.cornerRadius = 2;
        cancelBtn.layer.borderColor = [UIColor grayColor].CGColor;
        cancelBtn.layer.borderWidth = 1;
        cancelBtn.backgroundColor = [UIColor whiteColor];
        [cancelBtn setTitleColor:[UIColor grayColor] forState:UIControlStateNormal];
        [cancelBtn setTitle:@"Nevermind" forState:UIControlStateNormal];
        imgCropperVC.cancelBtn = cancelBtn;
```