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/sqlite3userauth.h

@@ -1,97 +0,0 @@
-/*
-** 2014-09-08
-**
-** The author disclaims copyright to this source code.  In place of
-** a legal notice, here is a blessing:
-**
-**    May you do good and not evil.
-**    May you find forgiveness for yourself and forgive others.
-**    May you share freely, never taking more than you give.
-**
-*************************************************************************
-**
-** This file contains the application interface definitions for the
-** user-authentication extension feature.
-**
-** To compile with the user-authentication feature, append this file to
-** end of an SQLite amalgamation header file ("sqlite3.h"), then add
-** the SQLITE_USER_AUTHENTICATION compile-time option.  See the
-** user-auth.txt file in the same source directory as this file for
-** additional information.
-*/
-#ifdef SQLITE_USER_AUTHENTICATION
-/* clang-format off */
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-/*
-** If a database contains the SQLITE_USER table, then the
-** sqlite3_user_authenticate() interface must be invoked with an
-** appropriate username and password prior to enable read and write
-** access to the database.
-**
-** Return SQLITE_OK on success or SQLITE_ERROR if the username/password
-** combination is incorrect or unknown.
-**
-** If the SQLITE_USER table is not present in the database file, then
-** this interface is a harmless no-op returnning SQLITE_OK.
-*/
-int sqlite3_user_authenticate(
-  sqlite3 *db,           /* The database connection */
-  const char *zUsername, /* Username */
-  const char *aPW,       /* Password or credentials */
-  int nPW                /* Number of bytes in aPW[] */
-);
-
-/*
-** The sqlite3_user_add() interface can be used (by an admin user only)
-** to create a new user.  When called on a no-authentication-required
-** database, this routine converts the database into an authentication-
-** required database, automatically makes the added user an
-** administrator, and logs in the current connection as that user.
-** The sqlite3_user_add() interface only works for the "main" database, not
-** for any ATTACH-ed databases.  Any call to sqlite3_user_add() by a
-** non-admin user results in an error.
-*/
-int sqlite3_user_add(
-  sqlite3 *db,           /* Database connection */
-  const char *zUsername, /* Username to be added */
-  const char *aPW,       /* Password or credentials */
-  int nPW,               /* Number of bytes in aPW[] */
-  int isAdmin            /* True to give new user admin privilege */
-);
-
-/*
-** The sqlite3_user_change() interface can be used to change a users
-** login credentials or admin privilege.  Any user can change their own
-** login credentials.  Only an admin user can change another users login
-** credentials or admin privilege setting.  No user may change their own 
-** admin privilege setting.
-*/
-int sqlite3_user_change(
-  sqlite3 *db,           /* Database connection */
-  const char *zUsername, /* Username to change */
-  const char *aPW,       /* New password or credentials */
-  int nPW,               /* Number of bytes in aPW[] */
-  int isAdmin            /* Modified admin privilege for the user */
-);
-
-/*
-** The sqlite3_user_delete() interface can be used (by an admin user only)
-** to delete a user.  The currently logged-in user cannot be deleted,
-** which guarantees that there is always an admin user and hence that
-** the database cannot be converted into a no-authentication-required
-** database.
-*/
-int sqlite3_user_delete(
-  sqlite3 *db,           /* Database connection */
-  const char *zUsername  /* Username to remove */
-);
-
-#ifdef __cplusplus
-}  /* end of the 'extern "C"' block */
-#endif
-
-#endif /* SQLITE_USER_AUTHENTICATION */