STYLE: Small improvements ImageBase constructor, SetRequestedRegion, '\'
STYLE: Small improvements ImageBase constructor, SetRequestedRegion, '\'

Initialized ImageBase::m_OffsetTable (a 'C array' of integers) by curly braces,
`{}`, in constructor member-initializer-list, instead of calling `memset`.

Removed check if m_RequestedRegion != region before ImageRegion assignment, as
this assignment is already very fast and `noexcept`. Note that this apparently
unnecessary 'if' was there already in 2001 (in Code/Common/itkImageBase.txx),
SHA-1: 73e22b2cb3fa156192f819c3d11706f86b6c9845

Removed dangling backslash, `\`, from PrintSelf, introduced in 2005 (in
Code/Common/itkImageBase.txx), SHA-1: 7510eae6effdf82a9b0307983dec0942d316f32b

blowekamp/ITK,blowekamp/ITK,richardbeare/ITK,LucasGandel/ITK,fbudin69500/ITK,Kitware/ITK,thewtex/ITK,InsightSoftwareConsortium/ITK,InsightSoftwareConsortium/ITK,vfonov/ITK,blowekamp/ITK,blowekamp/ITK,malaterre/ITK,LucasGandel/ITK,InsightSoftwareConsortium/ITK,vfonov/ITK,fbudin69500/ITK,BRAINSia/ITK,fbudin69500/ITK,Kitware/ITK,Kitware/ITK,LucasGandel/ITK,InsightSoftwareConsortium/ITK,fbudin69500/ITK,BRAINSia/ITK,hjmjohnson/ITK,malaterre/ITK,vfonov/ITK,malaterre/ITK,malaterre/ITK,hjmjohnson/ITK,InsightSoftwareConsortium/ITK,thewtex/ITK,BRAINSia/ITK,blowekamp/ITK,hjmjohnson/ITK,LucasGandel/ITK,hjmjohnson/ITK,hjmjohnson/ITK,thewtex/ITK,fbudin69500/ITK,thewtex/ITK,malaterre/ITK,vfonov/ITK,blowekamp/ITK,richardbeare/ITK,LucasGandel/ITK,vfonov/ITK,richardbeare/ITK,InsightSoftwareConsortium/ITK,thewtex/ITK,hjmjohnson/ITK,LucasGandel/ITK,thewtex/ITK,Kitware/ITK,richardbeare/ITK,vfonov/ITK,vfonov/ITK,richardbeare/ITK,Kitware/ITK,richardbeare/ITK,BRAINSia/ITK,fbudin69500/ITK,fbudin69500/ITK,malaterre/ITK,malaterre/ITK,BRAINSia/ITK,InsightSoftwareConsortium/ITK,vfonov/ITK,richardbeare/ITK,vfonov/ITK,LucasGandel/ITK,Kitware/ITK,fbudin69500/ITK,blowekamp/ITK,BRAINSia/ITK,thewtex/ITK,blowekamp/ITK,BRAINSia/ITK,malaterre/ITK,malaterre/ITK,Kitware/ITK,hjmjohnson/ITK,LucasGandel/ITK