SIX 2.2.1

• No longer require setting NITF_PLUGIN_PATH or calling six::loadPluginDir() when reading or writing SICDs or SIDDs. Instead, the underlying handler is linked in statically. If you are using SIX in your own build system, you will now need to link in an additional static library containing this handler.
• Support for reading and writing SICD 1.2
• crop_sicd now handles finding schema path correctly when the application is specified without a path (due to it being on your PATH)
• Previously, writing a SICD required either a) all of the pixels to be available in contiguous memory or b) all of the pixels to be available on demand via an io::InputStream (perhaps from a file). Added SICDWriteControl to support writing a SICD gradually as pixels are available. Pixels can be written in any order by providing the offset and dimensions each write, calling save() as many times as required.