Revert usage of joda-time to decrease needed dependencies and size of shaded jar.
Add additonal tags.
Merge pull request #1 from mfriedenhagen/develop

Create shaded jar and introduce joda-time as SimpleDateFormat is not threadsafe
Merge pull request #2 from mfriedenhagen/SimpleDateFormat

Switch back to SimpleDateFormat
Merge pull request #3 from mfriedenhagen/SimpleDateFormat-with-tags

Simple date format with tags