Add configuration file

[b-gyula]

An external (YAML/HOCON) configuration file shall be possible to add as program argument, that contains additional info cannot be retrieved from the jar:

• Column tag type mapping: The column tag is used in several changes, but only a reduced set of the attributes are used and the Liquibase code does not reflect it. Mostly ColumnConfig is used. There is also AddColumnConfig, but the generator might not be able to retrieve that type. There needs to be a section in the configuration file, where the {parent change name} -> {column type name} mapping can be defined. These types are expected to be already defined in the XSD.

• type mapping: There needs to be a section for {java type} -> {xml type} mappings

• additional description section: for each change/property additional description shall be possible to added