Coverity scan fixes CID : 982002 through 982054 (all ostream related)

git-svn-id: svn://dev.exiv2.org/svn@3281 b7c8b350-86e7-0310-a4b4-de8f6a8f16a3
CID: 1227096/7.  Pointer not initialized in constructor.

git-svn-id: svn://dev.exiv2.org/svn@3282 b7c8b350-86e7-0310-a4b4-de8f6a8f16a3
Fixed MinGW compilation error in jp2image.cpp u_int32_t not defined (in stdint.h/Linux, types.h/Mac)
This is an unexpected new defect as MinGW has previously build OK.

git-svn-id: svn://dev.exiv2.org/svn@3283 b7c8b350-86e7-0310-a4b4-de8f6a8f16a3