Misc. doc/script/test cleanup.

- fixing some Metrics::add_data() call signatures
- slight refactors to cluster framework @if and adding a NONE NodeType for
  so local_node_type() will return that instead of just emitting an error
  when cluster mode isn't enabled
- `make restdoc` target now uses bro's bare-mode
- bro scripts generated from bifs now really only live in the build/src/base/
  directory and changed the DocSourcesList.cmake to dynamically figure out
  what bifs exist by looking in src/ instead of build/src/
- add some missing @load dependencies

doc/scripts/CMakeLists.txt

@@ -119,7 +119,7 @@ macro(REST_TARGET srcDir broInput)
         ARGS -E remove_directory .state
         # generate the reST documentation using bro
         COMMAND BROPATH=${BROPATH}:${srcDir} ${CMAKE_BINARY_DIR}/src/bro
-        ARGS --doc-scripts ${broInput} || (rm -rf .state *.log *.rst && exit 1)
+        ARGS -b -Z ${broInput} || (rm -rf .state *.log *.rst && exit 1)
         # move generated doc into a new directory tree that
         # defines the final structure of documents
         COMMAND "${CMAKE_COMMAND}"