Tidied .gitignore

Added target directory and took root dir markers off the others.
Generating CSV from Tika MimeTypes object

Code now retrieves a string representation of the signatures and generates a
csv.
Merge branch 'master' of github.com:openplanets/format-corpus

Conflicts:
	tools/coverage/src/main/java/org/apache/tika/mime/TikaMimeType.java