ENH|API: IO registry exists
STY|API: pep8 and moved IO exceptions to skbio.io
TST: fixed StringIO for python3
TST: more python3 fixes
TST: assertTrue had 2 args, moved testclasses out of setup
DOC: added documentation about io
STY: minor changes
DOC: update .pyx docstring
Merge branch 'master' of https://github.com/biocore/scikit-bio into issue564

Conflicts:
	skbio/alignment/_alignment.py
	skbio/stats/distance/_base.py
	skbio/stats/ordination/tests/test_ordination.py
	skbio/tree/_tree.py
	skbio/tree/tests/test_tree.py
	skbio/util/__init__.py
Add timestamp checks to checklist.py for Cython code

Compares the timestamps of generated C files and Cython files to ensure that Cython files are not newer than the generated C file.
DOC: add changelog mention
Update generated C code

Thanks checklist.py :P
Merge pull request #609 from jairideout/checklist-cython-timestamps

Add Cython/C file timestamp checking to checklist.py
DOC/ENH: loosened concept of filehandling in procedural implementations and added convenience identifier for blank files
QSEQ parsing function and iterator.
Merge pull request #610 from laurentluce/qseq_parsing_changelog

ChangeLog - QSEQ parsing function and iterator.
TST: 100% branch coverage
Merge branch 'master' of https://github.com/biocore/scikit-bio into issue564
TST: fixed for python 3
Fix unit test name in pairwise tests