SSL.Cipher: Survive without Crypto.Arctwo and Crypto.IDEA.

Arctwo isn't available in old releases of Nettle,
and IDEA may be disabled in some versions of Nettle.
Calendar: Set timezone UTC for the 2040-11-08 test

If this is not done, it is possible to get the error "Time is out of
range for Timezone.localtime()".
test_pike.pike: Double the watchdog timeout

This compensates for the increase in amount of tests since 2005 when
the old timeout was selected.
Image.WebP: Check that the library exists, not just the headers
Build system: Improved simulation of dynamic modules.

Dynamic modules are now simulated with static modules when
not available. This includes having stub *.so files that
are loaded with load_module().

This fixes issues with eg loading Nettle without dynamic modules.
Smartlink: Added some runtime debug.

Setting the environment variable SMARTLINK_DEBUG now
causes smartlink to print the generated command line.

Also added support for compiling smartlink outside of configure.
Building: Fixed dependencies in Shuffler.

The Shuffler module failed to build if dependencies were up to
date, but the module never had been built, in which case make
would complain about there being no rule for "sources.h".