add support for getting decision function / probability estimates
add a one-class SDM implementation; no parameter tuning yet

should add tuning using e.g. something based on
    An Approach to Choosing Gaussian Kernel Parameter for One-Class SVMs
    via Tightness Detecting.
    Huangang Wang, Lin Zhang, Yingchao Xiao, and Wenli Xu.
    2012 4th International Conference on Intelligent Human-Machine Systems
    and Cybernetics (IHMSC), pp. 318-323.
    http://ieeexplore.ieee.org/lpdocs/epic03/wrapper.htm?arnumber=6305786
or
    Some properties of the Gaussian kernel for one class learning.
    Paul Evangelista, Mark Embrechts, and Boleslaw Szymanski.
    ICANN, 2007 pp. 269-278.
    http://www.springerlink.com/index/45802w50439x3788.pdf
or similar,

or maybe just with CV using...what?