Escape special characters in to_latex()
Merge pull request #5374 from bjornarneson/patch-1

Escape special characters in to_latex() output
PERF: vbenches for DataFrame.apply
PERF: perf enhancements for DataFrame.apply (GH6013)
TST: check appropriate tests for apply
PERF: allow apply to use the fast-path in mixed type frames except where datelike
      are present