Plot and compare histograms; pretty by default

Compares multiple sets of data elegantly. Set bins and axis bounds to be appropriate for the data.

Summary of what function does:
1) Automatically sets the number and range of the bins to be appropriate for the data.
2) Compares multiple sets of data elegantly on one or more plots, with legend or titles. It also graphs the mean and standard deviations. It can also plot the median and mode.
3) Outputs text with the useful statistics for each distribution.
4) Allows for changing many more parameters
Highlighted features (see below for details)
'boxplot' adds boxplots to the graphs
'separate' to plot each set on its own axis, but with the same bounds
'binfactor' change the number of bins used, larger value =more bins
'samebins' force all bins to be the same for all plots
'legend' add a legend in the graph (default for structs)
'noerror' remove the mean and std plot from the graph
'median' add the median of the data to the graph
'text' return many details about each graph even if not plotted
Syntax:
t = nhist(Y) bins the elements of Y into equally spaced containers
and returns a string with information about the distributions.
If Y is a cell array or a structure nhist will make graph the
binned (discrete) probability density function of each data
set for comparison on the same graph. It will return A cell
array or structure which includes a string for each set of
data.

[t, N, X]= nhist(...) also returns the number of items in each bin, N,
and the locations of the left edges of each bin. If Y is a
cell array or structure then the output is in the same form.

nhist(Y,'PropertyName', . . . )
nhist(Y,'PropertyName',PropertyValue, . . . )

% Examples
Cell array example:
A={randn(1,10^5),randn(10^3,1)+1};
nhist(A,'legend',{'u=0','u=1'});
nhist(A,'legend',{'u=0','u=1'},'separate');

Structure example:
A.zero=randn(1,10^5); A.one=randn(10^3,1)+1;
nhist(A);
nhist(A,'color','summer')
nhist(A,'color',[.3 .8 .3],'separate','median','noerror')
nhist(A,'binfactor',4)
nhist(A,'samebins')
nhist(A,'median','noerror')