autoreconf -i warnings => option 'subdir-objects' is disabled

[tseemann]

src/Makefile.am:26: warning: source file '../tests/check-snp-sites.c' is in a subdirectory,
src/Makefile.am:26: but option 'subdir-objects' is disabled
automake: warning: possible forward-incompatibility.
automake: At least a source file is in a subdirectory, but the 'subdir-objects'
automake: automake option hasn't been enabled.  For now, the corresponding output
automake: object file(s) will be placed in the top-level directory.  However,
automake: this behaviour will change in future Automake versions: they will
automake: unconditionally cause object files to be placed in the same subdirectory
automake: of the corresponding sources.
automake: You are advised to start using 'subdir-objects' option throughout your
automake: project, to avoid future incompatibilities.
src/Makefile.am:26: warning: source file '../tests/check-vcf.c' is in a subdirectory,
src/Makefile.am:26: but option 'subdir-objects' is disabled
src/Makefile.am:26: warning: source file '../tests/helper-methods.c' is in a subdirectory,
src/Makefile.am:26: but option 'subdir-objects' is disabled
src/Makefile.am:26: warning: source file '../tests/run-all-tests.c' is in a subdirectory,
src/Makefile.am:26: but option 'subdir-objects' is disabled

[andrewjpage]

added subdirs to version 2.1.0 so the warning has gone away