Also remove package and module names from classes and functions.
Also remove stix2.base from docs. We hide all private classes and
functions from the docs, so the only thing the documentation for base
included was STIXJSONEncoder.
Defining a custom object/observable/extension class with no custom
__init__() function would result in an `AttributeError` or `TypeError`,
depending on if the class sub-classed `object` or not.
- Test markings functions with both dictionaries and our _STIXBase-derived
classes as input.
- Slightly improve test coverage.
- Drop Python 2.6 support.
In ObservableProperty.clean(), parse_observable() will handle the issue
of non-cyber observable objects being presnt in an observable property.
The line raising a ValueError would not be reached so it was removed.
if no properties are passed to _check_at_least_one_property assume its all properties
when extensions are involved always check them in _check_at_least_one_property (caused by raising the exception on the enclosing type)
added _check_object_constaints to extensions, where appropriate
Added three new exceptions: DependentPropertiestError, AtLeastOnePropertyError, MutuallyExclusivePropertiesError
Added tests for NetworkTraffic, Process, URL, WindowsRegistryKey and X509Certificate
Added error tests for EmailMessage, NetworkTraffic, Artifact,
Added interproperty checker methods to the base class: _check_mutually_exclusive_properties, _check_at_least_one_property and _check_properties_dependency
Added interproperty checkers to Artifact, EmailMIMEComponent, EmailMessage, NetworkTraffic
Made NetworkTraffic.protocols required
Added X509V3ExtenstionsType class
Use EmbeddedObjectProperty for X509Certificate.x509_v3_extensions
uncomment test_file_example_encryption_error
added _check_object_constrains and properties_populated to base class
added ObjectConstraintError
added _check_object_constrains for File
added some test cases
in Observable constructor permit no _valid_refs in kwargs
in Observable._check_property ensure that the prop_name is in the kwargs
Chris Lenk