fn tests: document writing functional tests
fn tests: enable testing on Travis
fn tests: pocount no args
fn tests: pocount -h test
fn tests: pocount of single po file
fn tests: pocount mutually exclusive options
fn tests: pocount non-existant file
fn tests: pofilter listfilters
fn tests: pofilter --manpage
fn tests: prop2po no param
fn tests: prop2po simple file conversion
fn tests: prop2po processing directories
fn tests: prop2po with templates