#9671: Implement a histogram
Added code to handle the minmax data for a list of datasets the same as a single one.
Changed bar_chart to histogram. Removed docs that didn't fit. Changed default bin number to 10 not fifty. Exposed more of the matplotlib options.
No Subject. Modified: histogram.py
animate: Pass keyword arguments to plot constructor.

Some keyword arguments are only effective if passed to the plot.plot factory
function.  Passing them when saving the image doesn't have the same effect.
One example is xmin and xmax, which will affect the plot range as well.
So this change here should avoid a regression we've been observing.
Merge tag '6.4.beta4' into ticket/16570

Sage version 6.4.beta4
Mark some animation tests as long time.

This is the result of running the test suite with the --warn-long option.
Minor improvements to aminate documentation.

Some changes to make things look nicer: unified spacing and indenting, more
reasonable size of output figure, and one cross reference so we don't have
to duplicate documentation for online help.
Improve some more animation examples.

This addresses issues identified by Jakob Kroeker in #16570.
The change avoids overwriting the `dir` builtin in examples.
It adjusts some more animations to avoid varying or clobbered axes,
by fixing the range or by omitting the axes altogether.
fixed max y-axis range to 4 for the x^2 example
Merge branch 'develop' into histogram
Improve initial histogram work

Add better examples
Fix multiple data set plotting
Fix tests, etc.
Lots more histogram examples and "allowed" options.
Clean up mpfr, mpfi, mpc declarations
Fix docstring style
GLPK update.
Update GLPK to 4.55. Keep vanilla upstream tarball.
A few fixes for GLPK update to 4.55.
Refrain autotools from regenerating its files when configuring GLPK.
zlib is a dependency of GLPK as we don't use the upstream shipped version.