This function computes a multiple sequence alignment given a set of sequences in a Fasta object,
see readFasta for more on Fasta objects.
It is merely a wrapper for the function named in machine to avoid explicit writing and reading of files.
This function should only be used for small data sets, since no result files are stored. For heavier jobs,
use the machine function directly.
At present, the only machine function implemented is muscle, but other third-party machines
may be included later.
Note that this function will run muscle with default settings, which is fine for small data sets.