This commit documents the OPENSSL_VERSION_TEXT which is currently
missing in the man page.
Reviewed-by: NTim Hudson <tjh@openssl.org>
Reviewed-by: NRichard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/7301)

(cherry picked from commit 7c69495712e3dc9aa8db38271f0c3faeb2037165)