ENH: Use Tiff version dependent field type enable LSM

LSMImageIO was naively dependent on the ITK tiff library, when only
the return type of TIFFFieldWithTag changed between tiff library
versions. All dependencies of LSM and SYSTEM_TIFF have been removed.

Change-Id: Ibf4fc743e49de7d514b1410df28be1fc3e28d4d5
DOC: Fix instances of class documentation outside itk namespace

Change-Id: Ib6cee1b4c6516f7d09f8bab1167ce740e86f664e
Merge topic 'doc_namespace'

f92efa0 DOC: Fix instances of class documentation outside itk namespace
Merge topic 'FixLSMSystemTIFF'

e189a5c ENH: Use Tiff version dependent field type enable LSM