First non-alpha release

A few things were cleaned up before the full 0.1.0 release, as well as a few features added that were in progress.

• Added a command-line script runner. The runner can run any Groovy script, which will be able to use all Tabitha classes.
• Rows can be copied much easier with the addition of Row#copyOf().
• It is now easier to apply a function to a whole row with Row#map().
• RowReader#EMPTY was renamed to RowReader#VOID and RowWriter#NULL renamed to RowWriter#VOID to improve consistency.
• Added RowWriter#tee() for writting to multiple outputs simultaneously.
• Fix errors when reading from boolean and blank Excel cell types.
• Excel reader gives much more helpful error messages.
• Updated code styling and JavaDoc comments.

This release is meant to be used to gather interest in Tabitha's development, though using it for critical applications is not recommended.