cgm: add header to Makefile.am (found by make distcheck)
Fix shape.dtd to include rx, ry attributes for rect

found by make distcheck
vdx: write a single page size defintion ...

... Visio Viewer does not care, but LibreOffice does.
Also remove bogus optional attributes from Page tag.
vdx: adapt <ForeignData/> attributes and content

At least LibreOffice 4.2.4.2 is not happy with the padding
after base64 data, not even with the linebreak following. See:
https://bugs.freedesktop.org/show_bug.cgi?id=83275

The change in lib/prop_pixbuf.c to not put a linebreak into
the base64 data will have effect on other output as well,
but the tag directly following should not be a problem
anywhere.
Fix recently observed crash with "UML - Component Feature"

found by make distcheck running test-objects and toggling the
auto-routing via object menu function plus reverting it.

gdb --args .libs/objects ../objects//
[...]
Starting program: [...]/dia/tests/.libs/objects ../objects//
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/i386-linux-gnu/libthread_db.so.1".
/Dia/Objects/UML - Component Feature/Creation: OK
/Dia/Objects/UML - Component Feature/Copy: OK
/Dia/Objects/UML - Component Feature/Movement: OK
/Dia/Objects/UML - Component Feature/Change: OK
/Dia/Objects/UML - Component Feature/MoveHandle: OK
/Dia/Objects/UML - Component Feature/ConnectionPoints: OK
/Dia/Objects/UML - Component Feature/ObjectMenu: ***
Error in `[...]/dia/tests/.libs/objects': double free or corruption (fasttop): 0x0817b1d8 ***

Program received signal SIGABRT, Aborted.
0xb7fdd424 in __kernel_vsyscall ()
(gdb) bt
0  0xb7fdd424 in __kernel_vsyscall ()
1  0xb70dd577 in __GI_raise (sig=sig@entry=6)
   at ../nptl/sysdeps/unix/sysv/linux/raise.c:56
2  0xb70e09a3 in __GI_abort () at abort.c:89
3  0xb71186e3 in __libc_message (do_abort=do_abort@entry=1,
   fmt=fmt@entry=0xb72157bc "*** Error in `%s': %s: 0x%s ***\n")
   at ../sysdeps/posix/libc_fatal.c:175
4  0xb7122bca in malloc_printerr (action=<optimized out>,
   str=0xb7215980 "double free or corruption (fasttop)", ptr=0x817b1d8)
   at malloc.c:4996
5  0xb712383d in _int_free (av=0xb725b420 <main_arena>, p=<optimized out>,
   have_lock=0) at malloc.c:3840
6  0xb740bd30 in g_free (mem=0x817b1d8)
   at /build/buildd/glib2.0-2.40.0/./glib/gmem.c:190
7  0xb7f8613b in orthconn_destroy (orth=0x8189f98) at orth_conn.c:582
8  0x0804aef8 in _test_object_menu (user_data=0xb6c99284 <compfeat_type>)
   at test-objects.c:571