add test, deal with InRelease
refactor and move generation of the MetaIndex FileName out of the FindSrc()
further refactor, extract GetReleaseForSourceRecord() out of FindSrc(), write out the selection notice to c1out to be consistent with the rest of the source
add test for aptget source for unavailable package
refactor FindSrc()
use MetaIndexFile() instead of MetaIndexURI()
add #ifdefed ABI break & cleaner solution once the abi break is in place