* use different data types for commands and responses
* use variable length responses
* maintain client/flasher compatibility with old format (e.g. when using old bootloader)
* maintain bootloader compatibility with old format (e.g. when using old or RRG flasher.exe)
* fix length of version string in appmain.c
* merge cmd.c into usb_cdc.c
* move back usb_cdc.[ch] to common/
* declare low level functions usb_read() and usb_write() and more functions as static
* use cmd_receive() in bootrom.c and appmain.c
* remove unused memory wasting csrTab[100] in usb_cdc.c
* replace more byte_t by uint8_t
* more whitespace fixes
* move cmd.[ch] and usb_cdc.[ch] to armsrc
* sorting out #includes
* replace byte_t by uint8_t
* some reformatting
* whitespace fixes
* (no functional changes)
