tesla-test should depend on libtesla, too.
Provide stub tesla_{enter,exit}_context().

These functions will be called instead of tesla_update_state when we are informing libtesla of context entry/exit events.
Call tesla_{enter,exit}_context().

These functions don't do anything yet, but we now call them correctly from instrumentation.
Drop unused comment line.
Put 'printf' block between 'preamble' and 'entry'.

This is the control flow order, and it's easier to read.
Drop all printing from tesla_update_state.

This is the first step in cleaning up our debug/testing infrastructure.
Drop a DEBUG_NAME #define.
More informative print_{*} event handlers.
Update tests to use new test/debug update.
Trivial: whitespace.
Merge branch 'master' into explicit-init-cleanup
Trivial: re-add merged-out newline.