Adding failing test case for #5
Ensure ancestors are loaded when setting post URL.

Fixes #5.
Remove `bu_navigation_pull_page` and test coverage.
Add non-persistent cache group.

Cache results of `bu_navigation_load_sections()`.
Supersedes static variable caching in `_bu_navigation_page_uri_ancestors()`.
Cleanup

Move loop detection in `bu_navigation_get_page_uri()`.
Add "post_parent" field to missing ancestors.
Refactoring and cleanup.

Extract post-specific logic in bu_navigation_get_urls() in to separate functions
Switch to static variables for caching in bu_navigation_get_page_uri()
Don't return absolute URLs if ancestors aren't found in bu_navigation_get_page_uri()
Adding doc blocks for new functions.
Cleanup in `_bu_navigation_page_uri_ancestors`.

Use late priority for field filter to ensure it wins.
Comment rewrite.
Formatting cleanup.

Spaces to tabs for bu-navigation-labels.php.
Fixed bad method name in navigation test case.

Formatting.
Test coverage for new library permalink functions.

- Ensure our functions return the same results as the functions `get_permalink()` uses.
- Adjustments to library functions to fix issues uncovered by said test cases.
Don't escape navigation label.
Version bumps to 1.2
Readme updates.
Replace constant with string for text domain.
Removing old BU localization.

"Site Design" is now "Appearance".
Removing localized strings from unit tests.
Regenerated POT file.
Comment cleanup.
Merge branch 'release/1.2'