[kmseqfile] remove iterator functions
[benchmarks] remove seqfile iterator functions

We'll use the iterator macros from now on. A  little less pretty but way
faster & more flexible.
[kmlib.h] catch-all header includes all others
[test/data] add bad fastq files for testing
[CMakeLists] use all warning cflags for all builds

Use the long list of errors for all build types not just debug builds.
[kmzfile] fix bug in zfgetc EOF behaviour

EOF was never returned by zfgetc, as we did not allow eof to be set and
returned in the same call.
[kmseq] fix warnings in kmseq
[benchmarks] fix compiler warnings
[test_seqfile] better seqfile_read fastq tests