BUG: ReachedTargetPoints not set for OneTarget

When the m_TargetReachedMode was set to OneTarget, the
m_ReachedTargetPoints was always null after running the filter.
This has now been corrected by adding the target point to the
m_ReachedTargetPoints when it is reached.  This was not a problem when
setting m_TargetReachedMode to SomeTargets or AllTargets.
In addition, when m_TargetReachedMode was set to OneTarget or
NoTargets, the program would crash if the m_ReachedTargetPoints
structure was queried: for example when using
filter->GetReachedTargetPoints()->size().  This has also been
corrected by always initializing the m_ReachedTargetPoints structure
in the Initialize method.

Change-Id: I70afb74e337fe97230a76597be23e036e6c21b57
BUG: GDCM pixel spacing of ultrasound images.

The pixel spacing of certain ultrasound DICOM images has not been read
properly. Added an else branch in
gdcmImageHelper::GetUltraSoundSpacingValueFromSequence
that handles this issue.

Change-Id: I009f3601b342e44e78448767b7ec0c88df0cb386
Merge topic 'UltraSoundPixelSpacing'

76a3f83 BUG: GDCM pixel spacing of ultrasound images.
Merge topic 'FastMarchingUpwindGradientFix'

041d30f BUG: ReachedTargetPoints not set for OneTarget