imagemagick: copy *-config files to staging dir

We need to copy MagickWand-config, which handles pkg-config data, to the
staging dir, so that dependent packages can use it.  php7-pecl-imagick,
for example, may otherwise use an eventual host-installed file, causing
compilation to fail.  There's also a MagickCore-config file that does
the same thing for the MagickCore library, so a *-config wilcard is used
to handle all cases.

Since configure is called with --prefix=/usr, use $(SED) to change
definition of prefix and exec_prefix lines in *-config from /usr to
$(STAGING_DIR)/usr.

Signed-off-by: Eneas U de Queiroz <cotequeiroz@gmail.com>

multimedia/imagemagick/Makefile

@@ -8,7 +8,7 @@ include $(TOPDIR)/rules.mk
 PKG_NAME:=imagemagick
 PKG_VERSION:=7.0.9
 PKG_REVISION:=5
-PKG_RELEASE:=2
+PKG_RELEASE:=3
 PKG_MAINTAINER:=Val Kulkov <val.kulkov@gmail.com>
 
 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION)-$(PKG_REVISION).tar.gz
@@ -126,6 +126,13 @@ define Build/InstallDev
 	$(INSTALL_DATA) \
 		$(PKG_INSTALL_DIR)/usr/lib/pkgconfig/* \
 		$(1)/usr/lib/pkgconfig/
+
+	$(INSTALL_DIR) $(1)/usr/bin
+	$(INSTALL_BIN) \
+		$(PKG_INSTALL_DIR)/usr/bin/*-config \
+		$(1)/usr/bin/
+	$(SED) 's|prefix=/usr|prefix=$(STAGING_DIR)/usr|' \
+		$(1)/usr/bin/*-config
 endef
 
 IMlibdir:=usr/lib/ImageMagick-$(PKG_VERSION)