support rfc2397 data protocol

[Leo Savernik]

Hello,

As konqueror cannot handle mhtml (rfc2557) and hand-creating mhtml files is 
rather clunky, I propose the support of rfc2397 "The 'data' url scheme".
See: http://www.ietf.org/rfc/rfc2397.txt

data urls make writing some testcases infinitely easier, so I think konqueror 
should support them, too (Mozilla does it already).

I volunteer to implement it, of course. However, before I start implementing 
I'd like to have the following issues cleared and I hope that you kfm 
developers can give me some hints.

Implement rfc2397 as a kioslave kio_data?
Advantages:
- all security checks done to kioslaves would apply to data urls as well
- other applications can make use of data urls not anticipated today
Disadvantages:
- data is for small immediate data, doesn't justify either asynchronous 
processing nor process starting overhead (as kioslaves imply)

Implement as konqueror implementation detail like the "about:" protocol?
Efficient, but restricted to konqueror.

mfg
	Leo