Cleanups of lzma support

- fix inclusion of the separated file
- use namespaced name for the 4 non-static routines
- add padding after external structures included in-situ
- add new requirement to spec file
- general cleanup of code
diff --git a/libxml.spec.in b/libxml.spec.in
index 688811a..03eb24e 100644
--- a/libxml.spec.in
+++ b/libxml.spec.in
@@ -6,7 +6,7 @@
 Group: Development/Libraries
 Source: ftp://xmlsoft.org/libxml2/libxml2-%{version}.tar.gz
 BuildRoot: %{_tmppath}/%{name}-%{version}-%{release}-root
-BuildRequires: python python-devel zlib-devel pkgconfig
+BuildRequires: python python-devel zlib-devel pkgconfig xz-devel
 URL: http://xmlsoft.org/
 
 %description
@@ -25,6 +25,7 @@
 Group: Development/Libraries
 Requires: libxml2 = %{version}-%{release}
 Requires: zlib-devel
+Requires: xz-devel
 Requires: pkgconfig
 
 %description devel