removed doc strings for tests as discussed recently
renamed identifier as id
renamed identifier/identifiers to id/ids for consistency with other objects
added first pass at translate method and stubbed out ProteinSequence object to return from translate
first pass at adding has_terminal_stop method and tests
first pass at adding has_leading_start method and tests
added Protein IUPAC alphabets, tests, etc
fixed documentation error
cleaning up code
added error checking and more tests
deleted some methods - going to create better versions of these
removed the concept of NucleotideSequence's having a GeneticCode - instead they will be passed to GeneticCodes
added failing doc test
added failing tests
fixes #326
fixed based on comment from @wasade
renamed method
addressing comments from @ElBrogrammer
more work on docs
doc improvement