libxslt: revision bump to address open CVEs

- Add patches copied from Debian to address open CVEs
- Update mail address of maintainer
- Fix a typo
- Add --disable-silent-rules for verbose build output

Signed-off-by: Sebastian Kemper <sebastian_ml@gmx.net>

libs/libxslt/patches/0014-Handle-negative-xsl-number-values.patch

@@ -0,0 +1,51 @@
+From 69ec3da1b653024aca6515ddd4adc91919dd188e Mon Sep 17 00:00:00 2001
+From: Nick Wellnhofer <wellnhofer@aevum.de>
+Date: Sun, 10 Apr 2016 12:51:57 +0200
+Subject: [PATCH] Handle negative xsl:number values
+
+According to XSLT 2.0, negative values are a non-recoverable dynamic error.
+Print an error message and treat negative values as zero.
+
+Fixes an OOB array access in xsltNumberFormatAlpha.
+---
+ libxslt/numbers.c | 17 ++++++++++++++++-
+ 1 file changed, 16 insertions(+), 1 deletion(-)
+
+diff --git a/libxslt/numbers.c b/libxslt/numbers.c
+index eb087bc..a3cabcf 100644
+--- a/libxslt/numbers.c
++++ b/libxslt/numbers.c
+@@ -246,7 +246,7 @@ xsltNumberFormatAlpha(xmlBufferPtr buffer,
+ 	number--;
+ 	*(--pointer) = alpha_list[((int)fmod(number, alpha_size))];
+ 	number /= alpha_size;
+-	if (fabs(number) < 1.0)
++	if (number < 1.0)
+ 	    break; /* for */
+     }
+     xmlBufferCCat(buffer, pointer);
+@@ -442,6 +442,21 @@ xsltNumberFormatInsertNumbers(xsltNumberDataPtr data,
+ 	number = numbers[(numbers_max - 1) - i];
+         /* Round to nearest like XSLT 2.0 */
+         number = floor(number + 0.5);
++        /*
++         * XSLT 1.0 isn't clear on how to handle negative numbers, but XSLT
++         * 2.0 says:
++         *
++         *     It is a non-recoverable dynamic error if any undiscarded item
++         *     in the atomized sequence supplied as the value of the value
++         *     attribute of xsl:number cannot be converted to an integer, or
++         *     if the resulting integer is less than 0 (zero).
++         */
++        if (number < 0.0) {
++            xsltTransformError(NULL, NULL, NULL,
++                    "xsl-number : negative value\n");
++            /* Recover by treating negative values as zero. */
++            number = 0.0;
++        }
+ 	if (i < tokens->nTokens) {
+ 	  /*
+ 	   * The "n"th format token will be used to format the "n"th
+-- 
+2.8.1
+