ENH: Remove unneeded restriction on low. Closes #867.
MAINT: Remove broken function. Keep deprecation. Closes #781.
Fixes issue #832

https://github.com/statsmodels/statsmodels/issues/832

Two changes:
1) Clean up and fix the ipython notebook script.
2) Small cleanup on corresponding example to ensure that they match.
3) Change plot style on rlm example to make a larger plot.
Merge pull request #894 from jseabold/remove-margeff

MAINT: Remove broken function. Keep deprecation. Closes #781. (PR #894)
Merge pull request #893 from jseabold/fix-filter-check

ENH: Remove unneeded restriction on low. Closes #867.  (PR #893)
Merge pull request #895 from guyrt/fix-notebook-errors

Doc fixes closes #832  (PR #895, discussion in PR #892 )
ENH: add original quantile_regression
DOC: first example for quantilereg
DOC: sandbox examples quantile regression: move first, add new
STY: add whitespace, fix some undefined objects in unused code (pylint)
REF: some code comments, adjustments in unused code
REF move and rename quantreg
ENH: quantreg initial
bug
new kernels
bandwidth
add engel dataset for quantreg tests
add date
parzen kernel
np.percentile -> stats.scoreatpercentile