Merge topic 'SIMPLEITK-521_AddImageRegistrationMethodv4'

1995e2bd ENH: Add scales estimator option for regular step optimizer
94ae7dd7 Update arguments to ImageRegistrationMethod4
5d9a86de Update ImageRegistrationMethod4.py for v4 revision
6f455614 COMP: Remove duplicate MetricType definition
fcd9cf81 remove renaming of lambda
f7778b82 Add estimate learning rate frequency to gradient descent optimizers
aa43f291 Update registration example2
81fe096f Update StopDescription after execution
d77c093a Adding GradientDescentLineSearch optimizer
b9cb55a9 Adding regular step gradient descent magnitude tolerance
2f0c4151 Adding ConjugateGradientLineSearchOptimizer
a4a0d20b Add LBFGSB Optimizer
ed01cb36 rename minimum convergence criteria to be prefixed with convergence
e1e4fadb Adding convergence parameters to gradient descent optimizer
2da7cef7 explicitly set using gradient image
41ad9c26 Set default number of levels to 1
...
Merge topic 'SIMPLEITK-543_UpgradeITKTowards4.6'

9a9c7cfb Updating ITK super to master on 4/14/14
Merge branch 'master' into next

Change-Id: If377740e67e239e37f616697f6dde75dea06f710