Semi-automatically taking the the misc-include-cleaner warnings
by clang-tidy and fixing files to be self-contained.
Change-Id: Iaaa2b2ec9d6dcce547fa5cb6b4f056dfc8c781ff
Also introduce an always-failing 'reader' for unknown formats.
So we don't have to check reader==NULL, code is more regular.
-> We can get read of specific ReadPNG(), ReadJPEG(), ... declaration and use.
Change-Id: I290759705420878f00c7223c726d4ad404afd9c4