Release 1.4.12

• fixed some parser bugs with comment handling
• implemented an "unparser" to produce RDL source from JSON representation
• added base path feature to rdl
• include file name a type or resource was included from as an x_* annotation
• refactored external generators into "plugins", including both a generator and/or an importer
• added swagger importer
• fixed a variety of minor swagger generator bugs
• allowed -b base CLI option to pass through to external generators