message: change sizepolicy, so when changing to maximize mode, the TreeView will not be expanded
diff: @@ -95,6 +95,8 @@ DoubleTreeWidget::DoubleTreeWidget(const git::Repository &repo, QWidget *parent)
  assert(index == DoubleTreeWidget::Blame);
  index = mFileView->addWidget(mDiffView);
  assert(index == DoubleTreeWidget::Diff);
  + mEditor->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
  + mDiffView->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
  const QButtonGroup* viewGroup = segmentedButton->buttonGroup();
  QHBoxLayout* buttonLayout = new QHBoxLayout();
  @@ -114,6 +116,7 @@ DoubleTreeWidget::DoubleTreeWidget(const git::Repository &repo, QWidget *parent)
  QVBoxLayout* vBoxLayout = new QVBoxLayout();
  QLabel* label = new QLabel(tr("Staged Files"));
  stagedFiles = new TreeView(this, "Staged");
  + stagedFiles->setSizePolicy(QSizePolicy::Minimum, QSizePolicy::Expanding);
  mDiffTreeModel = new DiffTreeModel(repo, this);
  mDiffView->setModel(mDiffTreeModel);
  TreeProxy* treewrapperStaged = new TreeProxy(true, this);
  @@ -138,6 +141,7 @@ DoubleTreeWidget::DoubleTreeWidget(const git::Repository &repo, QWidget *parent)
  vBoxLayout = new QVBoxLayout();
  mUnstagedCommitedFiles = new QLabel(kUnstagedFiles);
  unstagedFiles = new TreeView(this, "Unstaged");
  + unstagedFiles->setSizePolicy(QSizePolicy::Minimum, QSizePolicy::Expanding);
  TreeProxy* treewrapperUnstaged = new TreeProxy(false, this);
  treewrapperUnstaged->setSourceModel(mDiffTreeModel);
  unstagedFiles->setModel(treewrapperUnstaged);
  