Add a way for the application to get OpenSSL configuration data

OpenSSL_version(OPENSSL_DIR) gives you a nicely formatted string for
display, but if all you really want is the directory itself, you were
forced to parsed the string.

This introduces a new function to get diverse configuration data from
the library, OPENSSL_info().  This works the same way as
OpenSSL_version(), but has its own series of types, currently
including:

OPENSSL_INFO_CONFIG_DIR         returns OPENSSLDIR
OPENSSL_INFO_ENGINES_DIR        returns ENGINESDIR
OPENSSL_INFO_MODULES_DIR        returns MODULESDIR
OPENSSL_INFO_DSO_EXTENSION      returns DSO_EXTENSION

OPENSSL_INFO_DIR_FILENAME_SEPARATOR     returns directory/filename separator
OPENSSL_INFO_LIST_SEPARATOR             returns list separator

For scripting purposes, this also adds the command 'openssl info'.

Reviewed-by: Paul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/8709)