from_SeqRecord method

[manulera]

Hi @BjornFJohansson, I noticed that this method does not call the init function, and this could be bug-prone. For example, I had not noticed that the new property of Dseqrecord, source was not being instantiated when reading from files because there the files are generated without calling init.

Do you think we could change this function to use init? Otherwise if we change properties we must make sure that they are the same.

Also, now this equality comparison is false because of this (I added it to the tests), but I am not sure it should be false.

assert Dseqrecord("AAA") != Dseqrecord.from_SeqRecord(SeqRecord("AAA"))

[BjornFJohansson]

I am leaning towards removing most of them for both Dseq and Dseqrecord. They were put there to speed up some operations, but they are only used internally.