libxslt: Fix xslt-config invocation of xml2-config

Fixes #360.

packages/libxslt/build.sh

@@ -1,7 +1,9 @@
 TERMUX_PKG_HOMEPAGE=http://xmlsoft.org/libxslt/
 TERMUX_PKG_DESCRIPTION="XSLT processing library"
 TERMUX_PKG_VERSION=1.1.29
+TERMUX_PKG_BUILD_REVISION=1
 TERMUX_PKG_SRCURL=ftp://xmlsoft.org/libxslt/libxslt-${TERMUX_PKG_VERSION}.tar.gz
 TERMUX_PKG_EXTRA_CONFIGURE_ARGS="--without-python"
 TERMUX_PKG_DEPENDS="libxml2,libgcrypt"
+TERMUX_PKG_DEVPACKAGE_DEPENDS="libxml2-dev"
 TERMUX_PKG_INCLUDE_IN_DEVPACKAGE="bin/xslt-config lib/xsltConf.sh"

packages/libxslt/xslt-config.in.patch

@@ -0,0 +1,15 @@
+diff -u -r ../libxslt-1.1.29/xslt-config.in ./xslt-config.in
+--- ../libxslt-1.1.29/xslt-config.in	2015-05-10 10:11:30.000000000 -0400
++++ ./xslt-config.in	2016-07-19 08:16:16.959043088 -0400
+@@ -89,9 +89,9 @@
+     shift
+ done
+ 
+-the_libs="@XSLT_LIBDIR@ @XSLT_LIBS@ @EXTRA_LIBS@"
++the_libs="@XSLT_LIBS@ @EXTRA_LIBS@"
+ if test "$includedir" != "/usr/include"; then
+-    the_flags="$the_flags -I$includedir `@XML_CONFIG@ --cflags`"
++    the_flags="$the_flags -I$includedir `@TERMUX_PREFIX@/bin/xml2-config --cflags`"
+ else
+     the_flags="$the_flags `@XML_CONFIG@ --cflags`"
+ fi