Safety net: don't allow numbers in SetGrid

... otherwise bad things might happen.
Bugfix when searching through directories

When attr is not define, we shouldn't ask for details. I am not sure
why attr is not defined in some cases (symlinks for example?).


Closes #23
Remove default width for images
Better handling of saved pages
Select page number on PlaceObject

We can now do this:

<PlaceObject page="123" ...> to jump forward to the page, put the object and
go back to the current page.
vreference in PlaceObject

This allows objects to be aligned with the bottom border at the given row.
Merge branch 'hotfix_v1.6' into develop_v1.7

Bugfix when searching through directories
Add command line options 'profile'

Internal use only. This allows me to easily find out where the
bottlenecks are.
Merge branch 'develop_v1.7' into develop

Add command line options 'profile'
Bugfix when searching through directories
Safety net: don't allow numbers in SetGrid
Small various bugfixes