Metalinks Code

- Patch from Peter Poeml applied.
- Moved char* to string, cleanup.

code cleanup

minor bugfixes for jigdo

closer to jigdo download support, file size is correct, but bad checksum for ISO

Jigdo ISO generation support almost works now, but not quite

now handles the mirrorlists section for better segmented downloading

downloading now works for jigdo files, still need to assemble ISO

Added initial support for conversion of .jidgo to .metalink (not quite complete), downloading still in progress

Updated for 4.1 release, includes a few bugfixes based on running the automated tests

Real file download progress being reported for non-segmented downloads now