libtorrent: Switch to static library.

libtorrent is only used by rtorrent. Switch to a static library to save
space.

Removed libsigc++ dependency. It seems it's not needed.

Signed-off-by: Rosen Penev <rosenp@gmail.com>

libs/libtorrent/Makefile

@@ -9,7 +9,7 @@ include $(TOPDIR)/rules.mk
 
 PKG_NAME:=libtorrent
 PKG_VERSION:=0.13.8
-PKG_RELEASE:=1
+PKG_RELEASE:=2
 
 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.gz
 PKG_SOURCE_URL:=https://codeload.github.com/rakshasa/libtorrent/tar.gz/v$(PKG_VERSION)?
@@ -22,7 +22,6 @@ PKG_LICENSE_FILES:=COPYING
 PKG_FIXUP:=autoreconf
 PKG_INSTALL:=1
 PKG_BUILD_PARALLEL:=1
-PKG_REMOVE_FILES:=autogen.sh
 
 include $(INCLUDE_DIR)/package.mk
 
@@ -31,7 +30,7 @@ define Package/libtorrent
   CATEGORY:=Libraries
   TITLE:=Rakshasa's BitTorrent library
   URL:=https://rakshasa.github.io/rtorrent/
-  DEPENDS:=+libopenssl +libsigcxx +zlib
+  DEPENDS:=+libopenssl +libstdcpp +zlib
 endef
 
 define Package/libtorrent/description
@@ -59,14 +58,9 @@ define Build/InstallDev
 	$(INSTALL_DIR) $(1)/usr/include
 	$(CP) $(PKG_INSTALL_DIR)/usr/include/torrent $(1)/usr/include/
 	$(INSTALL_DIR) $(1)/usr/lib
-	$(CP) $(PKG_INSTALL_DIR)/usr/lib/libtorrent.{a,so*} $(1)/usr/lib/
+	$(CP) $(PKG_INSTALL_DIR)/usr/lib/libtorrent.a $(1)/usr/lib/
 	$(INSTALL_DIR) $(1)/usr/lib/pkgconfig
 	$(CP) $(PKG_INSTALL_DIR)/usr/lib/pkgconfig/libtorrent.pc $(1)/usr/lib/pkgconfig/
 endef
 
-define Package/libtorrent/install
-	$(INSTALL_DIR) $(1)/usr/lib
-	$(CP) $(PKG_INSTALL_DIR)/usr/lib/libtorrent.so.* $(1)/usr/lib/
-endef
-
 $(eval $(call BuildPackage,libtorrent))