* Fix deadlock condition due to improper mutex lock use.
* Refactor and improve test suite result reporting.
* Add echo command.
* Do not print prompt character and help message in scripted mode.
* Add Raspberry Pi GPIO support functions.
* Add timestamps to the test suite.
* Add information on required headers for each module of the test
software.
Yes, a more modular layout, albeit the fact that this is still but one
single source file. However, this reorganization will better
facilitate breaking this up into module files.
