Utilities: Enable relative URI retrieval
Optimize component file registration path: Use relative URI instead of file path

* Closes #73
Merge branch 'iss-73' into develop
Base: Use relative URI to enqueue client files
JS: Confirm jQuery available before running code with dependencies
Merge branch 'opt-jquery-load' into develop
Fix: Component handle name generation
Remove deprecated code

* `slb_register_theme()`
* `SLB_Lightbox::get_theme()`
Refactor Field classes
Defer loading until WP init
Refactor class autoloader

* Move to separate file
* Defer loading until init
Remove redundant license text
Cleanup inline documentation
Merge branch 'opt-init' into develop
Viewer layout: Use fixed offset
Default theme/Transition/Complete: Get accurate viewer height

Optimizes viewer positioning
Default theme/Transition/Complete: Cleanup code

* Inline documentation
* Standardize animation speed
* Defer DOM manipulation/query until necessary

* Resolves #70
* Resolves #69
* Resolves #74
* Resolves #66
Merge branch 'iss-70' into develop
Theme: Add sorting to `get_ancestors()`
Themes: Defer style loading until after document loaded