ENH: Cppcheck fixes for version v1.59.

ENH: Cppcheck found a variety of scope issues with variables which
     needed to be corrected. Further, additional suppressions had
     to be added to the TubeTK suppression file (primarily for unused
     function warnings and unread variable warnings).
Change-Id: I8f8a6fbc6182c633c8c8ef4a11ddd32e5e367621
Merge topic 'rk-NewCppCheckIssues'

89a809c ENH: Cppcheck fixes for version v1.59.