Allow moving off bounds in projected gradient.

The current implementation does not allow you to move off the
bounds (lower/upper) once you have gotten on them, this allows you
to move off of the bound.

Please note that more testing should be done to ensure that this does
not introduce oscillations into the optimization routine.

SimPEG/Optimization.py

@@ -990,4 +990,18 @@ class ProjectedGNCG(BFGS, Minimize, Remember):
                     cgFlag = 1
                 # End CG Iterations
 
+            # Take a gradient step on the active cells if exist
+            if temp != self.xc.size:
+
+                rhs_a = (Active) * -self.g
+
+                dm_i = max( abs( delx ) )
+                dm_a = max( abs(rhs_a) )
+
+                delx = delx + rhs_a * dm_i / dm_a /10.
+
+            # Only keep gradients going in the right direction on the active set
+            indx = ((self.xc<=self.lower) & (delx < 0)) | ((self.xc>=self.upper) & (delx > 0))
+            delx[indx] = 0.
+
             return delx