Rather than assume all dependencies are required for all programs, split them out. This will make packaging easier, as well as splitting the code to use subprojects. Note that due to the use of config.h semantics, in most cases the got_compat.h header file is now at the top of the .c file it is included in, so that it can handle the system header inclusion properly.

Simply the SHA detection by not predicating on libcrypto, but instead checking individual header files.

Remove sha1.h as this is found portably across systems.

In preparation for wide sha256 support; stsp@ agrees. Change done mechanically with find . -iname \*.[cy] -exec sam {} + X ,x/<sha1\.h>/i/\n#include <sha2.h>

ok op@

Needed by future gotd(8), where progress reports will be sent to a network socket, rather than a local terminal.

Remove certain headers which are included portably.

Needed by future gotd(8). ok op@