Improvement: more pythonic style for dds.keep

[tjhunter]

The current style for dds.keep may not seem natural for python users:

dds.keep("/path", function, x, y=1)

It does not seem that a function is being called. Instead, the following style could be used:

dds.keep("/path", function)(x, y=1)

This would make it more clear that a function is being called, and it makes the transition from the initial code (function(x, y=1)) easier.