Version comparison and build-skipping is broken

Before: the list of releases in `version` could be updated and the build script would build what is needed to be built according to `versions` if it was not already available in dist.ipfs.io

Now: if the `version` file is updated to, for example, cleanup older version or remove older rc releases that should not be published anymore, the comparison between the existing version file and the current file returns a wrong list of releases to build because it lists lines that are in a position that was not expected, regardless of whether they are already built or not.

This was done in 0e510b94d62b0c1a0783c347c5d9d918fc363bee and later in 19448fd1 . It seems there is an assumption that version files are append-only, but it is not the case. The way it was done before (or not done) just worked.

@aschmahmann @olizilla