bump version to 0.20.0-dev after tagging 0.19.0
update tests to be compatible with django 1.5 (secret key required)
add ID attribute to root mods element
whitespace/linter cleanup
correct path for changelog inclusion in sphinx docs
update eadmap with support for digital archival object tag (dao)
add entry to changelog about mods id attribute contributed by bcail
try alternate squid startup to see if it helps xsd timeout on travis-ci
run travis-ci tests without squid/http proxy
declare xlink namespace in a way that makes it easier to re-use
restore pip dev requirements file for generating documentation on readthedocs.org
add support for multiple titles, and let them have displayLabels
add more date types in OriginInfo
specified 0.20 as version in develop branch

specified secret key
add xmlmap mapping for DateField and DateListField
minimal support for xmlmap datefield in xmlobjectform
document datefield in changelog