2 bugfixes on WOAdaptor

Hi,

calling http-Sources for Adaptor config using the ifNotModifiedSince-Header was a bad idea,
as merging the config from changed and unchanged sources does not work properly. Probably
almost nobody makes use of http sources (but me), but its a fixed bug, anyway.

IIS 7 has a serious issue on streaming downloads. This fix enforces IIS 6 behaviour and ensures
proper download streaming.

A new version number identifies this version.

When then change is accepted, I will supply the new IIS binaries to Pascal

Regards, Markus