add support for special characters in source URIs

e.g. maildir:/home/scott/Maildir/%5BGmail%5D.All%20Mail

dry it up a bit

exclude directories from maildir email list

remove test file
add support for special chars in mbox source uri
more special characters
source uri: set up tests

stub maildir and mbox tests

experiments with tests

got tests for special characters working

use the same approach for mbox and maildir testing

use the old minitest naming to make Travis happy

remove extra line in email
ignore trustdb.gpg
history: source uris