DOC: show the rplot import at the top level of the trellis plotting section
DOC: tweak docstring
CLN: elminate testing warning on 2.6, deprecated exception idiom
fix multiindex xs slicing bug
VB: add vbench for df.xs across row/col
BLD: travis network cache
BLD: use_build_cache.py - fix 2to3 caching and messages
Merge branch 'travis_make_it_faster'

* travis_make_it_faster:
  BLD: use_build_cache.py - fix 2to3 caching and messages
  BLD: travis network cache
PLEASE_TRAVIS_FASTER
Merge pull request #3383 from y-p/travis_make_it_faster

Travis-CI: Allow network cache opt-in for whitelisted forks
BUG: fix travis net cache
BLD/BUG: travis scripts should appreciate politeness in body as well as subject
BUG: GH3380 groupby will handle mutation on a DataFrame group's columns and fallback

     to non-fast apply

DOC: PTF
Merge pull request #3378 from cpcloud/multiindex-bug

multiindex xs slicing bug fix - thanks!
BUG: encoding detection should accept variations on 'ascii' GH3360
DOC: ref / val caveat, point at pandas methods

This in part addresses #3340.

I added a few comments in the doc that point users ad using the pandas
at, iat, loc, iloc, etc. methods and included an example similar to
the one exposed in #3340 that addresses some of the reference / value
intricaies encountered with pandas and numpy objects.

CLN: cleanup + edits - addresses recent discussion

CLN: cleanup II

CLN: wrap at 80 chars.

took care of both documents.
Merge pull request #3399 from dengemann/ref_value_data_access_doc

DOC: ref / val caveat, point at pandas methods - thanks!
Merge pull request #3384 from jreback/groupby_mutate

BUG: GH3380 groupby will handle mutation on a DataFrame group's columns
DOC: cookbook updates
     updates in indexing.rst for view vs copy
DOC: indexing.rst updates