Support building plugins from Bro installation root

As opposed to plugins depending on a Bro source/build tree.  This
required installing various Bro headers, BinPAC and it's headers,
bifcl, and Bro's custom CMake modules.

src/CMakeLists.txt

@@ -400,3 +400,23 @@ install(CODE "
        ${BRO_SCRIPT_INSTALL_PATH}/policy/tuning/logs-to-elasticsearch.bro
    )
 ")
+
+install(DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/
+        DESTINATION include/bro
+        FILES_MATCHING
+        PATTERN "*.h"
+        PATTERN "*.pac"
+        PATTERN "3rdparty/*" EXCLUDE
+)
+
+install(DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/
+        DESTINATION include/bro
+        FILES_MATCHING
+        PATTERN "*.bif.func_h"
+        PATTERN "*.bif.netvar_h"
+        PATTERN "*.bif.h"
+)
+
+install(FILES ${CMAKE_CURRENT_SOURCE_DIR}/3rdparty/sqlite3.h
+        DESTINATION include/bro/3rdparty
+)