Safer, mutex-locked, serial interaction to make fast paced exchanges ok.  Mods to library structure to make inclusion in other software easier.
Reorganization for version 1.2. New support for "streaming" uploads, as required by SerialUI 1.7.
Re-org to enhance portability/reuse.  New support for SerialUI (1.7) "streaming" prompts.
Rename of a few legacy defines...