Add (restore?) the ability to build without trashing the source tree

You may now do:

mkdir build
cd build
../configure
./audacity

And all but one directory will remain unmolested...no more object files
in "src".

And if you look carefully, you'll see that the newly built "audacity" is
copied to the top of the build tree...no more having to use "src/audacity"
to run.

You can of course still do the configure from the top and get all of the
objects strewn about the tree.

I still haven't figured out how to keep the locale directory from getting
soiled.  I'm not really sure there's a way around it really.

lib-src/audacity-patches.txt

@@ -121,6 +121,7 @@ Version in Audacity SVN: 0.1.1
 Patches: 
    * "libsoxr/configure" file: modified cmake params
    * add-make-check-support.patch: Add a check target for GNU Autotools integration.
+   * libsoxr-srcdir.patch: Adds srcdir handling
 Upstream Version: 0.1.1
 
 libvamp
@@ -129,6 +130,7 @@ Library to load and use VAMP plug-ins. http://www.vamp-plugins.org/
 Version in Audacity SVN: 2.5
 Patches: fix-linkage-against-dl.patch: Fix linkage against dl for hostsdk library.
          fix-all-target.patch: Fix all target to not build disabled targets.
+         libvamp-srcdir.patch: Adds srcdir handling
 Upstream Version: 2.5
 
 libvorbis
@@ -244,6 +246,7 @@ https://sourceforge.net/tracker/index.php?func=detail&aid=2561247&group_id=17779
 because attachements there don't seem to work.
 autotools.patch: Fix all autotools warnings.
 autotools-fix-make-dist.patch: Correct file lists to make dist target work.
+sbsms-srcdir.patch: Adds srcdir handling
 
 soundtouch
 ----------