graph.js: Wrap svg elements into a namespace

Signed-off-by: Diego Giovane Pasqualin <dpasqualin@c3sl.ufpr.br>
graph.js: Add transition to nodes and edges (work in progress)

All transitions are starting from (graph height/2), because we don't save
the previous position of the node. If we do, something goes wrong on
dpll.js, need to figure it out why

Signed-off-by: Diego Giovane Pasqualin <dpasqualin@c3sl.ufpr.br>
dpll.js: Don't update the graph after the dpll algorithm finishes

Signed-off-by: Diego Giovane Pasqualin <dpasqualin@c3sl.ufpr.br>
No need to copy search tree on every graph update

This allows search tree updates with nodes/edges positions, thus improving
transition smoothness

Signed-off-by: Diego Giovane Pasqualin <dpasqualin@c3sl.ufpr.br>
Fix necessity to clean the graph on every update

This makes the transitions way smoother

Signed-off-by: Diego Giovane Pasqualin <dpasqualin@c3sl.ufpr.br>
Add tooltip on the nodes showing the formula with assingment applied

Signed-off-by: Diego Giovane Pasqualin <dpasqualin@c3sl.ufpr.br>