Compile sqlite with FTS3 enhanced query syntax enabled (#562)

Fixes #550

This adds three compilation flags to the embedded sqlite module:

- `-DSQLITE_ENABLE_FTS3` to explicitly enable FTS3 support (which AFAIK
is already enabled by default)
- `-DSQLITE_ENABLE_FTS3_PARENTHESIS` to enable the enhanced FTS3 query
syntax (which isn't enabled by default)
- `-DSQLITE_ENABLE_FTS3_TOKENIZER` to enable the two-argument version of
the `fts3_tokenizer()` interface. It still has to be enabled on the
connection-level using `Connection.setconfig`

All those flags are enabled by default in the Debian build of SQLite,
and probably in other distributions as well.

Author: sandhose

cpython-unix/build-sqlite.sh

@@ -22,7 +22,7 @@ elif [ "${TARGET_TRIPLE}" = "x86_64-apple-ios" ]; then
     CONFIGURE_FLAGS="${CONFIGURE_FLAGS} ac_cv_search_system=no"
 fi
 
-CFLAGS="${EXTRA_TARGET_CFLAGS} -DSQLITE_ENABLE_DBSTAT_VTAB -fPIC" CPPFLAGS="${EXTRA_TARGET_CFLAGS} -fPIC" LDFLAGS="${EXTRA_TARGET_LDFLAGS}" ./configure ${CONFIGURE_FLAGS}
+CFLAGS="${EXTRA_TARGET_CFLAGS} -DSQLITE_ENABLE_DBSTAT_VTAB -DSQLITE_ENABLE_FTS3 -DSQLITE_ENABLE_FTS3_PARENTHESIS -DSQLITE_ENABLE_FTS3_TOKENIZER -fPIC" CPPFLAGS="${EXTRA_TARGET_CFLAGS} -fPIC" LDFLAGS="${EXTRA_TARGET_LDFLAGS}" ./configure ${CONFIGURE_FLAGS}
 
 make -j ${NUM_CPUS}
 make -j ${NUM_CPUS} install DESTDIR=${ROOT}/out