Add Modules subdirs to SRCDIRS to generate directories for out-of-tree
object files.
Debian wants ncurses lib. Works on Fedora, too.
Debian also needs pkg-config to detect correct flags.
Remove more outdated comments. Makefile now tracks header dependencies
-lintl is injected by configure when needed. Build _dbm with
gdbm-compat.
Group some modules by purpose. socket, select, and mmap work on Windows,
too.
The new checks are only executed when one or more OpenSSL-related files are modified. The checks run a handful of networking and hashing test suites. All SSL checks are optional. This PR also introduces ccache to speed up compilation. In common cases it speeds up configure and compile time from about 90 seconds to less than 30 seconds.
Signed-off-by: Christian Heimes <christian@python.org>