make 100% compatible with swift.py?

Make Env vars compatible with st?

Get and put the metadata in the libray (x-object-meta-mtime) when getting and putting a file?

st is setting this
'x-object-meta-mtime'

    getmtime(filename)
        Return the last modification time of a file, reported by os.stat().

>>> f = os.path.getmtime("z")
1347717491.343554
>>> print f
1347717491.34
>>> str(f)
'1347717491.34'
>>> "%d" % f
'1347717491'
>>> 

swift.py appears to be doing it wrong with str(float) which isn't a
good way of stringifying floats...

Make 

This also puts meta-mtime
https://github.com/gholt/swiftly

As an integer, but it does parse it as a float
subargs.append('x-object-meta-mtime:%d' % getmtime(options.input_))