3.4.0

• f28f4ce - release
• f4782d1 - correct some illogical in ComplexValueConverter
• e7645a2 - add builder method in ComplexValueConverter
• 0a2c0af - mark ComplexValueConverter as final
• be19a62 - add ComplexValueConverter
• bca6b48 - no comment on flat file
• d2bb6a5 - add a cache map to StorageAgent
• 0140233 - add StringConverter
• 03ff01d - less confusing naming in ValueConverter
• 8ab17d7 - mark as major update
• 489a010 - more intuitive ValueConverter for DataStorageSupplier
• 8be5337 - Bump org.sonatype.central:central-publishing-maven-plugin (#130)
• 1a741d0 - support commit/rollback in DataStorage
• 58c145c - don't have to check urgent mode when starting saving task
• a347174 - next development