Item permalink URL changes

Creates a new route for item permalinks. Updates the themes to use the new route. The existing route now forwards to the new route.
Fix broken link to custom posts in activity stream
Merge branch 'feature/item-permalink-updates' into develop
Fix tag pages not showing all posts with that tag

- Fix /items/tag pages using count_items_by_search() instead of
  count_item_by_tag() for figuring out pagination.
- Fix item_model count_items_by_tag() using depreciated getwhere()
  function.

Refs #38
More Accurately Calculate Which Tags Are Popular

- When requesting tags, only those of a published posts will be
  returned.
- tag_model get_all_tags() will calculate the number of items tagged
  dynatmically.
- The column count of the tags table is unnecessary, the column and
  related code will be removed when the database migration tool is
  built.

Refs #38
Merge branch 'master' into develop
Potential fix for page numbers > items tagged

- If tags were deleted but somehow the relationship still existed the
  left join would have counted those ones as well.

Refs #41
Merge pull request #41 from MitchellMcKenna/feature/more-accurate-tag-popularity

More Accurately Calculate Which Tags Are Popular
Update README.md to include Plugin Documentation
Merge branch 'master' into develop
Add docs for Themes to readme
Bump LifePress version to 0.3
Merge pull request #52 from MitchellMcKenna/develop

LifePress version 0.3