New formula: davmail

Closes #33416.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>
gettext 0.19.4
gettext: update 0.19.4 bottle.
pyqt: style nits
pyqt: don't open a GUI during brew test

Opening a GUI window during brew test leads to test failures on Yosemite.
pyqt: bottle against system Python
pyqt: update 4.11.1 bottle.