Update to consensus module and seqcons.

This pull request contains an updated version of the `consensusAlignment()` function from the `consensus` module an an updated version of the `seqcons` app. The `consensusAlignment()` function contains code from the ANISE insert assembler.

Ultimately, `seqcons2` should replace `seqcons`. A release of `seqcons` exists on http://packages.seqan.de, but we could also add a tag here before the replacement.

The `consensusAlignment()` function should be replaced by the new version.

The only thing missing in `seqcons2` is the undocumented FASTA file format from the `consensus` module which is a deletion candidate IMO and support for the AMOS format. The latter should be fairly easy to support through the store module.

However, when advertising `seqcons2` as a drop-in replacement for the Celeara Assembler consensus module, we need to test this and probably need an expert with CA. I do not know whether `seqcons` v1 works correctly with the AMOS format and I propose that we should only consider supporting AMOS when someone requests this.
On the other hand, why was it necessary to change it here? If there is no particular reason "" would be necessary for StringSet<char *> (I'm not sure if we ever tried it)