uninstalled.pc: add support for non libtool build systems

Currently the .la path is provided which requires to use libtool as
mentioned in the GStreamer manual section-helloworld-compilerun.html.
It is fine as long as the application is built using libtool.

So currently it is not possible to compile a GStreamer application
within gst-uninstalled with CMake or other build system different
than autotools.

This patch allows to do the following in gst-uninstalled env:
gcc test.c -o test $(pkg-config --cflags --libs gstreamer-1.0)
Previously it required to prepend libtool --mode=link

https://bugzilla.gnome.org/show_bug.cgi?id=720778

pkgconfig/gstreamer-base-uninstalled.pc.in

@@ -1,7 +1,7 @@
 # the standard variables don't make sense for an uninstalled copy
 prefix=
 exec_prefix=
-libdir=@abs_top_builddir@/libs/gst/base
+libdir=@abs_top_builddir@/libs/gst/base/.libs
 includedir=
 girdir=@abs_top_builddir@/libs/gst/base
 typelibdir=@abs_top_builddir@/libs/gst/base
@@ -11,5 +11,5 @@ Description: Base classes for GStreamer elements, Not Installed
 Requires: gstreamer-@GST_API_VERSION@ = @VERSION@
 Version: @VERSION@
 
-Libs: @abs_top_builddir@/libs/gst/base/libgstbase-@GST_API_VERSION@.la
+Libs: -L${libdir} -lgstbase-@GST_API_VERSION@
 Cflags: -I@abs_top_srcdir@/libs -I@abs_top_builddir@/libs

pkgconfig/gstreamer-check-uninstalled.pc.in

@@ -1,7 +1,7 @@
 # the standard variables don't make sense for an uninstalled copy
 prefix=
 exec_prefix=
-libdir=@abs_top_builddir@/libs/gst/check
+libdir=@abs_top_builddir@/libs/gst/check/.libs
 includedir=
 girdir=@abs_top_builddir@/libs/gst/check
 typelibdir=@abs_top_builddir@/libs/gst/check
@@ -11,5 +11,5 @@ Description: Unit testing helper library for GStreamer modules, Not Installed
 Requires: gstreamer-@GST_API_VERSION@ = @VERSION@
 Version: @VERSION@
 
-Libs: @abs_top_builddir@/libs/gst/check/libgstcheck-@GST_API_VERSION@.la @LIBM@
+Libs: -L${libdir} -lgstcheck-@GST_API_VERSION@ @LIBM@
 Cflags: -I@abs_top_srcdir@/libs -I@abs_top_builddir@/libs

pkgconfig/gstreamer-controller-uninstalled.pc.in

@@ -1,7 +1,7 @@
 # the standard variables don't make sense for an uninstalled copy
 prefix=
 exec_prefix=
-libdir=@abs_top_builddir@/libs/gst/controller
+libdir=@abs_top_builddir@/libs/gst/controller/.libs
 includedir=
 girdir=@abs_top_builddir@/libs/gst/controller
 typelibdir=@abs_top_builddir@/libs/gst/controller
@@ -11,5 +11,5 @@ Description: Dynamic parameter control for GStreamer elements, Not Installed
 Requires: gstreamer-@GST_API_VERSION@ = @VERSION@
 Version: @VERSION@
 
-Libs: @abs_top_builddir@/libs/gst/controller/libgstcontroller-@GST_API_VERSION@.la
+Libs: -L${libdir} -lgstcontroller-@GST_API_VERSION@
 Cflags: -I@abs_top_srcdir@/libs -I@abs_top_builddir@/libs

pkgconfig/gstreamer-net-uninstalled.pc.in

@@ -1,7 +1,7 @@
 # the standard variables don't make sense for an uninstalled copy
 prefix=
 exec_prefix=
-libdir=@abs_top_builddir@/libs/gst/net
+libdir=@abs_top_builddir@/libs/gst/net/.libs
 includedir=
 girdir=@abs_top_builddir@/libs/gst/net
 typelibdir=@abs_top_builddir@/libs/gst/net
@@ -11,5 +11,5 @@ Description: Network-enabled GStreamer plug-ins and clocking, uninstalled
 Requires: gstreamer-@GST_API_VERSION@ = @VERSION@ gio-2.0
 Version: @VERSION@
 
-Libs: @abs_top_builddir@/libs/gst/net/libgstnet-@GST_API_VERSION@.la
+Libs: -L${libdir} -lgstnet-@GST_API_VERSION@
 Cflags: -I@abs_top_srcdir@/libs -I@abs_top_builddir@/libs

pkgconfig/gstreamer-uninstalled.pc.in

@@ -1,7 +1,7 @@
 # the standard variables don't make sense for an uninstalled copy
 prefix=
 exec_prefix=
-libdir=@abs_top_builddir@/gst
+libdir=@abs_top_builddir@/gst/.libs
 # includedir is builddir because it is used to find gstconfig.h in places
 includedir=@abs_top_builddir@
 toolsdir=@abs_top_builddir@/tools
@@ -16,6 +16,5 @@ Description: Streaming media framework, Not Installed
 Version: @VERSION@
 Requires: glib-2.0, gobject-2.0
 Requires.private: gmodule-no-export-2.0
-Libs: @abs_top_builddir@/gst/libgstreamer-@GST_API_VERSION@.la
+Libs: -L${libdir} -lgstreamer-@GST_API_VERSION@
-# FIXME: the libs dir doesn't really belong here
 Cflags: -I@abs_top_srcdir@ -I@abs_top_srcdir@/libs -I@abs_top_builddir@ -I@abs_top_builddir@/libs