fixing graph division
Merge pull request #558 from kreczko/fix_graph_division

fixing graph division
use asrootpy in List.__iter__ and ObjArray.__iter__
Merge pull request #559 from ndawe/master

[MRG] use asrootpy in List.__iter__ and ObjArray.__iter__
use keepalive in Legend.AddEntry
Merge pull request #560 from ndawe/master

[MRG] use keepalive in Legend.AddEntry
new measurement methods
return axes and axes bounds from plotting.utils.draw
Merge pull request #561 from ndawe/master

[MRG] new measurement methods
workspace.fit add return_nll argument
Merge pull request #562 from ndawe/master

[MRG] workspace.fit add return_nll
draw() if graph is the first object, don't use the A option since that draws lines on the plot for the axes
minor fix
Merge pull request #563 from ndawe/master

draw() if graph is the first object, don't use the A option
set yaxis and xaxis limits manually in the plot function
add graph.num_points setter and getter
new axes() on pads create and return axes
Merge pull request #564 from ndawe/master

[MRG] new axes() on pads create and return axes
_limits_helper: don't raise ValueError and instead return reasonable values if min=max
Merge pull request #565 from ndawe/master

[MRG] _limits_helper: don't raise ValueError