BUG: add fix for opening zero observation dta files
_sanitize_column now reports proper duplicate error
Merge branch 'issue_7432_resolve' of https://github.com/roblevy/pandas into roblevy-issue_7432_resolve
ERR: fixup exception reports for duplicate axis reindexing, related (GH7432)
Merge branch 'fix_empty_open' of https://github.com/bquistorff/pandas into bquistorff-fix_empty_open

Conflicts:
	doc/source/v0.14.1.txt
TST/CLN: centralize module check funcs