New function PKCS7_signatureVerify to allow the signing certificate to
be explicitly stated with PKCS#7 verify.

Also fix for util/mkerr.pl: if the -nostatic option is being used this will be
for an external library so the autogenerated C file should include the
header file as:
#include "any/path/to/header.h"
rather than the internal library form:
#include <openssl/header.h>

util/libeay.num

diff --git a/util/libeay.num b/util/libeay.num
index 36c0cd4..4c49be6 100755
--- a/util/libeay.num
+++ b/util/libeay.num
@@ -1817,3 +1817,4 @@
 sk_ASN1_OBJECT_insert                   1842
 sk_ASN1_OBJECT_push                     1843
 d2i_ASN1_SET_OF_ASN1_OBJECT             1844
+PKCS7_signatureVerify                   1845

util/mkerr.pl

diff --git a/util/mkerr.pl b/util/mkerr.pl
index 60a3028..4b3bccb 100644
--- a/util/mkerr.pl
+++ b/util/mkerr.pl
@@ -284,8 +284,14 @@
 
 	# Rewrite the C source file containing the error details.
 
-	$hfile =~ /([^\/]+)$/;
-	my $hincf = $1;
+	my $hincf;
+	if($static) {
+		$hfile =~ /([^\/]+)$/;
+		$hincf = "<openssl/$1>";
+	} else {
+		$hincf = "\"$hfile\"";
+	}
+
 
 	open (OUT,">$cfile") || die "Can't open $cfile for writing";
 
@@ -351,7 +357,7 @@
 
 #include <stdio.h>
 #include <openssl/err.h>
-#include <openssl/$hincf>
+#include $hincf
 
 /* BEGIN ERROR CODES */
 #ifndef NO_ERR