Maintenance and bugs fixes

Quick fixes

Maintenance & Bugs fixes

Glob() is expensive so cache the category files.

Fix theme

Theme copyright.

Added theme copyright for Twenty Fifteen & Twenty Sixteen.

Prepare quick release

Prepare quick release since even though only small changes but its
important. See commit #2fca100

Improving template engine

Improving template engine for more flexible theming. Add
cache.expiration.

Improvements

Update

Improve custom menu

Add active menu link to custom menu