Fix merging bug where downstream items somtimes got ignored if they appear after an upstream-only item. Also, reduce the severity of the validation error if a tech-domain is not recognised on a non-Foundation package.
The module FileCompare.pm needs an MD5 module. If present it will use Digest::MD5, because this is implemented in C and so is faster than this pure Perl version. However, Perl version 5.005_03 (the version currently shipped with the Symbian platform SDK) doesn't contain Digest::MD5. This module is therefore provided as a fall back.