Define base feature interfaces
Major revision of experimental seq packages

This is a major revision of the design of the experimental sequence and
feature packages that hopefully is cleaner in its approach.

 * sequtils provides functions that act directly on sequence types.
 * feat and Features are now an integrated component of sequences.
 * Interface definitions are more specific.
 * Low utility packages have been removed (bit packed, secondary quality
   types).
Further revision to seqs - input from Egon Elbre

Significant simplification: protein and nucleic merged into one branch
and run-time panics for misuse, rather than compile-time errors
(RevComp is the only method affected). This allows alot of code
reduction.
Fix nil alphabet Add bug

Adding to a multi with a nil Alpha would refuse fail since the added
seq's alphabet was not nil (i.e. not equal). Make a special case for
this.
Add fmt.Formatter support for linear sequences.
Revise quality filter function

Now can make arbitrary changes to sequence based on filter threshold.
Lagging change - Annotation is in seq

Change Annotation field to seq.Annotation.
Change name of Consensify field
s///g error

Lagging change of names collided with global replace.
Cleaner organisation of the consensus functions
Make better use of godoc organisation

Give types to QFilters and ConsenseFuncs to appropriately group them in
the docs.
Add name-less output flag.
Rower interface

A Rower is a multiple sequence type that can return a Row. A Row points
into the multiple sequence so that individual sequences can be
manipulated while aligned. This API change allows removal of the
Position type.
Fasta reader bug fix

Did not give informative error on reading non-fasta file.

Also change receiver names.
Further fasta and fastq bugfixes

Neither correctly handled long lines (i.e. greater tha line buffer
length).
Move majority of seq-dependent packages to exp/seq

This is a massive set of changes and brings significant improvements
(IMO) to sequence and feature handling.
Rename seq and annotation Copy* methods to Clone*

More idiomatic convention.
Lagging change

Replace Copy with Clone.
Change license

Now under BSD-like.
Revise matrix implementation

* No use of goroutines without justification.
* Clean up receiver names, returns etc.
* Improve allocations in String (TODO: write Format method).