sqlite3: add config options to disable FTS3 and RTREE

The full-text search engine version 3 (FTS3) and R*Tree (RTREE) modules are
enabled by default in sqlite3; add config options which allow to disable these
sqlite lib modules.
Disabling FTS3 reduces the so file with 475KB while disabling RTREE reduces
the so file with 121KB on x86 architecture.

Signed-off-by: Hans Dedecker <dedeckeh@gmail.com>

libs/sqlite3/Config.in

@@ -0,0 +1,18 @@
+menu "Configuration"
+	depends on PACKAGE_libsqlite3
+
+config SQLITE_FTS3
+	bool
+	prompt	"Enable FTS3"
+	help
+		"Enable support for full-text search version 3"
+	default y
+
+config SQLITE_RTREE
+	bool
+	prompt	"Enable RTREE"
+	help
+		"Enable support for the R*Tree index extension"
+	default y
+
+endmenu

libs/sqlite3/Makefile

@@ -9,7 +9,7 @@ include $(TOPDIR)/rules.mk
 
 PKG_NAME:=sqlite
 PKG_VERSION:=3210000
-PKG_RELEASE:=1
+PKG_RELEASE:=2
 
 PKG_SOURCE:=$(PKG_NAME)-autoconf-$(PKG_VERSION).tar.gz
 PKG_HASH:=d7dd516775005ad87a57f428b6f86afd206cb341722927f104d3f0cf65fbbbe3
@@ -24,6 +24,10 @@ PKG_FIXUP:=autoreconf
 
 PKG_INSTALL:=1
 
+PKG_CONFIG_DEPENDS := \
+	CONFIG_SQLITE_FTS3 \
+	CONFIG_SQLITE_RTREE
+
 include $(INCLUDE_DIR)/package.mk
 
 define Package/sqlite3/Default
@@ -52,6 +56,10 @@ $(call Package/sqlite3/Default/description)
  programs.
 endef
 
+define Package/libsqlite3/config
+  source "$(SOURCE)/Config.in"
+endef
+
 define Package/sqlite3-cli
   $(call Package/sqlite3/Default)
   SECTION:=utils
@@ -67,11 +75,20 @@ $(call Package/sqlite3/Default/description)
  formats.
 endef
 
+
 TARGET_CFLAGS += $(FPIC) \
 	-DSQLITE_ENABLE_UNLOCK_NOTIFY=1 \
 	-DHAVE_ISNAN=1 \
 	-DHAVE_MALLOC_USABLE_SIZE=1
 
+ifneq ($(CONFIG_SQLITE_FTS3),y)
+TARGET_CFLAGS += -USQLITE_ENABLE_FTS3
+endif
+
+ifneq ($(CONFIG_SQLITE_RTREE),y)
+TARGET_CFLAGS += -USQLITE_ENABLE_RTREE
+endif
+
 CONFIGURE_ARGS += \
 	--enable-shared \
 	--enable-static \