[libpng16] Made changes for compatibility with automake 1.14:
1) Added the 'compile' program to the list of programs that must be cleaned
in autogen.sh
2) Added 'subdir-objects' which causes .c files in sub-directories to be
compiled such that the corresponding .o files are also in the
sub-directory. This is because automake 1.14 warns that the
current behavior of compiling to the top level directory may be removed
in the future.
3) Updated dependencies on pnglibconf.h to match the new .o locations and
added all the files in contrib/libtests and contrib/tools that depend
on pnglibconf.h
4) Added 'BUILD_SOURCES = pnglibconf.h'; this is the automake recommended
way of handling the dependencies of sources that are machine generated;
unfortunately it only works if the user does 'make all' or 'make check',
so the dependencies (3) are still required.
5 files changed
