Merge branch 'master', remote branch 'upstream/master'
SQLA defaults set with text() throw an exception.

Code changed to allow for objects such as:
class User(Base):
    __tablename__ = 'user'
    id = Column(BigInteger(unsigned=True), default=text("uuid_short()"),
                primary_key=True, autoincrement=False)

default can't be interpretted before calling SQLA's backend so Colander's defaults are left blank and field is set to not be required (since it being left empty will call the default)
fixed tests to work properly in Python 3.3 and Python 2.6

There was a race condition in test_declarative_colums_overrides() that sometimes occurred causing later tests to fail.  The comment about the test not working in Python 2.6 may have been related to that, because it seems to be working now.
cleaned up default values for SchemaNode's default/missing

added tests
updated CHANGES
updated docs for changes to default/missing
fixed error in example code
fixes to make examples work
setup_schema takes 2 args
consolidated 'rules' into index.rst
missed some punctuation
don't need to manually install unittest2 any more
removed unused import; "not _ is None" changed to "is not None"
Merge branch 'master' of https://github.com/tisdall/ColanderAlchemy
"geting" changed to "getting"
"instatiating" to "instantiating"

There seems to be a weird mix of US and UK spelling in here (ie "customize" vs "customise"), but I don't know which one to favour (or "favor" as the case may be).
"represting" to "representing"; "situtation" to "situation"
allow passing instantiated colander types instead of just callables

If you need a type of `colander.Mapping(unknown='ignore')` you'd have
to create a wrapper as the code currently expects only callables
which return a colander type.  There's no reason (that I can see)
for this restriction so I changed it to accept either.
Merge branch 'dev' of https://github.com/tisdall/ColanderAlchemy
Merge pull request #32 from tisdall/master

SQLA default set with text() throws an exception.