Add empty methods to implement the copy and pattern copy.
Add new keys for new buttons in contextual menu.
Refactor identical parts in methods into a new method.
Implementation of the copy/past feature.
Refactor contextMenu method.
Fix a bug: when the copy buffer is empty doesn't show past action anymore.
Correct a french traduction.
Move isLeaf method from TreeWidgetJSON object to TreeWidgetItemJSON object.
Now if the user already open at least one file before, the open file window is browsing the directory of the last file opened.
Add cleanDataStructure function.
Implements pattern copy. Still have to implement patternPaste.
Implements browsing the tree using up and down arrows. The visualization of the data using the arrows isn't implemented yet.
Full support of 'arrow key deplacement' in the tree, implemented.
Refactor the way to extract the data using a function defined in tools.py
Add string for the pattern copy.
Fix issue #3: Finish implementation of the pattern copy.
Merge branch 'develop' into 'master'.