Update README.md and wavanalysisexample.py
Added code to calculate additional statistics - median and standard deviation- as well as summary statistics for the frequencies array. Added this data to the README; changed links in readme from speedcap (temporary image hoster) to photobucket (more permanent image hosting solution). Also noted that the number of frequencies given at any point in time is a function of the fourier transform size- .5x + 1 where x is the transform size. For example, we're using a transform size of 4096, so we get 2049 frequencies at any point in time; a transform size of 16 yields 9 frequencies at any point in time. This fact probably isn't useful but it's worth noting.