Managing branches

Right button click on section name shows a popup menu which Add Branch item. After clicking it:

1. A dialog should appear to add a new branch, validation of the input should be provided.
2. A combo box appears with the section this branch will appear in.

After adding a branch, it should appear in the tree without refreshing the page. Since it's a tree, there should be a possibility to collapse and expand particular sections.
Other items that should appear in the popup menu):

• Edit button: should appear which will show the same dialog as while creating the branch.
• Branch Permissions: shows the window with permissions (this button already there but it reacts on the selection of the branches).