Fix various issues that result in compiler warnings.

Prompted by a diff from Brent Cook.
Include openssl/evp.h for OPENSSL_add_all_algorithms_noconf().

From Brent Cook.
Add regression test for UTF8_{getc,putc}()
Enable the 3- and 4-byte sequence tests for UTF8_getc()
Add surrogate and out-of-range tests for UTF8_putc() on the assumption
we'll make it return -2.  Maybe.
Make this build cleanly even with UTF8_{putc,getc} moved from the
public header to the internal.  Make some variables unsigned to
eliminate some warnings
make this compile again - actually include stdio and friends ourselves.
remove OPENSSL_malloc and CRYPTO_malloc goo from the regress tests.
ok miod@ jsing@ guenther@
Add the RFC 7027 test vectors; from OpenSSL HEAD