Fix buildserver.YailEvalTests.

Fix buildserver.YailEvalTests so they run cleanly again. This involved
also removing a bunch of obsolete repl tests that were based on the
old telnet repl code.

Change-Id: Ia3cb5216292d34c4043382c11e283e443c9635ee
Fix Wrong Number of Arguments Error in runtime.scm

Error Handling for a Wrong Number of Arguments Error in runtime.scm
was itself buggy, resulting an a string coercion error occurring while
attempting to build the error to display.

Change-Id: Ia5c3d5eaf47e5aa28607e777b9a71ecdec763502
Quote Unicode Characters en-route to the Companion.

Change-Id: I81cd877dc08b858b8d22b95d1e05be72dd2e1718