Merge pull request #6 from bricebou/master

Extending alphabetical sorting
Merge pull request #8 from bricebou/master

Fixing https://github.com/DanReeves/picotags/issues/7
Merge pull request #9 from bricebou/master

Removing a personnal condition, better docs, special character support
Merge pull request #12 from bricebou/master

Add option to use custom template for tag pages
Merge pull request #15 from bricebou/master

Adding a test on $this->exclude_keys in case nothing is excluded