docx ST_VAnchor does not know "column", it should be "text"

Change-Id: I3a5ab08e349c5c071373cda2f62e3cea593e263c
export in .docx also vml mso-position-(horizontal|vertical)(-relative)

Change-Id: I65321bb6244e0e37ef673d726b698c3708711d53
proper reading of mso-position-(horizontal|vertical)(-relative)

Change-Id: I50f537c697f6e73c1fd150f3f03fc65b85ccbeaf
map PAGE_PRINT_AREA to VML's margin

That's what the code does elsewhere in this file, and also import does it.

Change-Id: I30e608f86a9cae66eed48dbb2e719b1455327ae3
map FRAME to VML's text

Again, that's what this file does elsewhere, that's what (incomplete) import
did before my changes, and it seems to match better the position that such
an element gets in Word.

Change-Id: Id09150eaaa505e6ddcd4baaf4a833000d52dd71d