Minor update to the LowLevel MassStorage device demo, so that the ReadInCommandBlock() performs the data OUT endpoint selection and packet arrival test.

Move over message ID specific header data to unions inside the standard TMC header structure, so that all header data is read in one chunk in the incomplete TMC demo.

Rename reserved members of all structs so that they are uniformly named across all demos/projects/bootloaders.

Added start of the Incomplete TMC demo's command parser code.

Add missing INTERRUPT_CONTROL_ENDPOINT compile time option to the Mass Storage device projects/demos and incomplete Test and Measurement Class demo, which was accidentally removed during the makefile updates.

Alter Test and Measurement Class demo's request handlers to accept, process and correctly return the fields indicated in the specification.

Add stream callback flags and class specific control request handler code to the incomplete Test and Measurement Class device demo.

Change over the keyboard demo's manufacturer name back to the primary author of the demo.

Convert over internal pseudo-function macros to true inline functions for added type-safety and compile-checking.