Add function to import IEDB native format

[burkesquires]

Add a function to natively read IEDB epitope format; such as "H25, H45, V46, N47, L496, S306, L307, P308, T333"

NOTE: Further enhance to allow for epitopes to be pasted that are discontinuous peptides on multi chains such as: "A: H25, H45, V46, N47, L496, S306, L307, P308, T333; B: D363, G364, W365, Q382, T385, Q386, I389, D390, T393, V396, N397, I400;"

Basically strip off the characters or better yet extract the characters and use them to find the reference sequence

[burkesquires]

Instead of having users copy and paste from IED, it would be better to accept an IEDB ID, get the epitope information AND the reference sequence that is part of the IEDB record. An ID such as 226309 with webpage here: http://www.iedb.org/assayId/1599742