Provide infrastructure to migrate legacy analyzers to Spicy.

As initial examples, this branch ports the Syslog and Finger analyzers
over. We leave the old analyzers in place for now and activate them
iff we compile without any Spicy.

Needs `zeek-spicy-infra` branches in `spicy/`, `spicy-plugin/`,
`CMake/`, and `zeek/zeek-testing-private`.

Note that the analyzer events remain associated with the Spicy plugin
for now: that's where they will show up with `-NN`, and also inside
the Zeekygen documentation.

We switch CMake over to linking the runtime library into the plugin,
vs. at the top-level through object libraries.

testing/scripts/diff-canonifier-external

@@ -25,5 +25,6 @@ $(dirname $0)/diff-remove-timestamps |
     $(dirname $0)/diff-remove-x509-names |
     $(dirname $0)/diff-sort-conn-service |
     $(dirname $0)/diff-sort-set-elements |
+    $(dirname $0)/diff-remove-spicy-abspath |
     $(dirname $0)/diff-sort |
     eval $addl

testing/scripts/diff-remove-spicy-abspath

@@ -0,0 +1,12 @@
+#!/usr/bin/env bash
+#
+# Replace absolute paths in Spicy error message with the basename. This is more
+# restrictive than diff-remove-abspath to avoid catching other stuff.
+
+if [ $(uname) == "Linux" ]; then
+    sed="sed -r"
+else
+    sed="sed -E"
+fi
+
+$sed 's#/([^:/]{1,}/){1,}([^:/]{1,}\.spicy[:,])#<...>/\2#g'

testing/scripts/have-spicy

@@ -1,6 +1,2 @@
 #!/bin/sh
-if grep -q "DISABLE_SPICY:BOOL=true" "${BUILD}"/CMakeCache.txt; then
-    return 1
-else
-    true
-fi
+"${BUILD}/zeek-config" --have-spicy-analyzers >/dev/null