COV: Fixing remaining coverity issues in Application engine (structurally dead code and unchecked dynamic cast)

COV: Fixing coverity issues 1266601, 1266589, 1266590, 1266591, 1266592, 1266593, 1266595, 1266597, 1266598, and 1266600 (Uninitialized scalar variable)

Drop reference to cmake macro CMAKE_IMPORT_BUILD_SETTINGS and
CMAKE_EXPORT_BUILD_SETTINGS. Those macros seems to do nothing since CMake
2.8. It should allow to compile current trunk with cmake 3.0 wainting for the
new modular OTB which rewrite completely cmake configuration.