Further polish SQLite vendoring

- Now integrated with `make tags` for Emacs IDE features
- Delete some old deprecated broken full-text search engines
- Rename .h → .inc files that don't meet our definition of header
- Make sure every #include line is normal form so tools understand

See #162

third_party/sqlite3/fts3.c

@@ -289,7 +289,7 @@
 */
 /* clang-format off */
 
-#include "third_party/sqlite3/fts3Int.h"
+#include "third_party/sqlite3/fts3Int.inc"
 #if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)
 
 #if defined(SQLITE_ENABLE_FTS3) && !defined(SQLITE_CORE)
@@ -300,7 +300,7 @@
 #include "libc/mem/mem.h"
 #include "libc/stdio/stdio.h"
 #include "libc/str/str.h"
-#include "third_party/sqlite3/fts3.h"
+#include "third_party/sqlite3/fts3.inc"
 #ifndef SQLITE_CORE
 #include "third_party/sqlite3/sqlite3ext.h"
 SQLITE_EXTENSION_INIT1