Initial boilerplate
Basic implementation of property data descriptor.

No type management or recursive containment yet.
Link to lxml.etree
Link to travis
Ensure that __init__ can be loaded; define api module for redeclarations.
Add type support to property
Allow property attributes, add @tag class decorator, and distinguish get/set type functions.
Implement typing of nested elements; still requires some iteration
All properties to be required and automatically created
Merge branch 'feature/childobjects' into develop
Improve handling of inheritance and defaults.
Handle mismatched tag.
Rework property typing to use classes and factory methods.

At the same time, switch to processing elements instead of element text,
so that nested classes use the same approach as string/int/long types and
so that more complex tree manipulations are possible.
Add list functions for elements with multiple children.
Improve list handling by adding _parent reference; then use reference for Jenkins parent link.
Simplify property declaration; derive name
Implement searching and filtering more cleanly.
Simpify attributes setting
Add publishing to travis
Merge branch 'release/1.0'