Added preemption to timer interrupts.
- Normalized use of the g_switch_flag across the timer and UART i-processes
- After these changes I am no longer seeing the "Should not get here!" message in the UART i-proc
- Also noticed performance improvement in printing characters in the simulator
Merge branch 'master' into stress-test
Using the new message-converting functions in the timer.
The timer can now send envelopes, and when this happens, the sender id now remains the same instead of being set to the timer's id.
Bunch of small but important stuff (see description)
- Hiding kernel-only message types from users
- Took out check for the 'Z' character in proc_a since KCD already does the checking for that
- Removed other unnecessary void* casts and unused "sender_id" variables in sys_proc.c