[Bug 25656] provide tool to set dpi for kdm

[Yogarine]

Public bug report changed:
https://launchpad.net/malone/bugs/25656

Comment:
Wouldn't it be more usefull to make the X.org configuration tool get the
default DPI's right (perhaps by even asking the size of the monitor
during configuration)? Novice users probably don't even know what DPI
stands for and what it does... They'll just notice that their fonts
strangely large / small.

These kind of things Should Just Work.