openssl: don't install manpages

This gets rid of ca. 1200 manpages in ssl/man/man[13].
libssh2: don't install manpages

This gets rid of ca. 160 manpages.

Also, drop nonexisting 'bin_PROGRAMS= sbin_PROGRAMS= html_DATA='.
sdl: don't install manpages

This gets rid of ca. 170 manpages.

Also, drop nonexisting 'bin_PROGRAMS= sbin_PROGRAMS= noinst_PROGRAMS='.
sdl2: Drop non-existing stuff

There are no 'bin_PROGRAMS= sbin_PROGRAMS= noinst_PROGRAMS=' in sdl2.
Merge pull request #471 from uwehermann/no_manpages

Don't install manpages and other cleanups