Add viewer index next to the mosquito
Add currentViewerIndex in buttleData
Assign node name to viewer index
Merge branch 'develop' of github.com:buttleofx/ButtleOFX into develop

Conflicts:
	buttleofx/data/buttleData.py
Fix bug

Fill mapViewerIndexToNodeName with None value
Fix bug - load graph.

Can display computed image after loading a graph.
Fix #42
Merge branch 'develop' of github.com:buttleofx/ButtleOFX into develop

Conflicts:
	buttleofx/data/buttleData.py
Expose emitViewerChangedSignal function to qml
Update viewer using emitViewerChangedSignal slot

When a mosquito is dropped and when the selected viewer is modified
Merge branch 'develop' of github.com:buttleofx/ButtleOFX into develop
Merge branch 'develop' of github.com:buttleofx/ButtleOFX into develop
Load graph : reorganize some code.
Save graph : improve saving.

Only save param which have changed (by manipulation of the user).
Merge branch 'develop' of github.com:buttleofx/ButtleOFX into develop

Conflicts:
	buttleofx/data/buttleData.py
Display of the tmpConnection (clic'drag)

Error when we try to update the canvas coordinates :
QPixmap::operator=: Cannot assign to pixmap during painting

issue #34
Merge branch 'develop' of github.com:buttleofx/ButtleOFX into develop
Load graph : loading without making useless copy.
Merge branch 'develop' of github.com:buttleofx/ButtleOFX into develop

Conflicts:
	buttleofx/data/buttleData.py
Save / load graph : consider several viewers.
fix #34