Unit tests for H2Database.

api/net/sf/briar/api/db/DatabaseComponent.java

components/net/sf/briar/db/Database.java

components/net/sf/briar/db/H2Database.java

components/net/sf/briar/db/JdbcDatabase.java

components/net/sf/briar/protocol/MessageImpl.java

test/build.xml

test/net/sf/briar/TestUtils.java

test/net/sf/briar/db/H2DatabaseTest.java

test/net/sf/briar/i18n/I18nTest.java

test/net/sf/briar/invitation/InvitationWorkerTest.java

test/net/sf/briar/setup/SetupWorkerTest.java

test/net/sf/briar/util/FileUtilsTest.java

test/net/sf/briar/util/ZipUtilsTest.java