Update libsndfile to 1.0.29pre2+git

This pulls in MANY (over 890) changes compared to our
from our current 1.0.24 version.

lib-src/libsndfile/regtest/Readme.txt

@@ -0,0 +1,108 @@
+sndfile-regtest
+===============
+
+The 'sndfile-regtest' program is a regression test-suite for libsndile.
+
+This program is intended to allow anyone who has an interest in the
+reliability and correctness of libsndfile to do their own regression
+testing. From the point of view of the libsndfile developers, this
+program now allows for distributed regression testing of libsndfile
+which will make libsndfile better.
+
+
+How Does it Work
+----------------
+Anyone who wishes to take part in the distributed regression testing of
+libsndfile can download the regression test program and install it.
+
+Once installed the user can start collecting files and adding them to
+their own personal database. Then, as new versions of libsndfile come
+out, the user should test the new library version against their database
+of files (instructions below).
+
+Any files which were successfully added to the database in the past but
+now fail the check with the new library version represent a regression.
+The user should then contact the libsndfile developers so that a copy
+of the test file can be made available to the developers.
+
+
+Requirements
+------------
+The regression test program uses sqlite3 as the database engine. On
+Debian, the required packages are :
+
+    sqlite3
+	libsqlite3-0
+	libsqlite3-dev
+
+but similar packages should be available on any other Linux style
+system.
+
+The regression test currently only compiles under Unix-like systems.
+At some time in the future the regression test will distributed along
+with the libsndfile source code distribution.
+
+
+Organization of Files
+---------------------
+The regession test program keeps its database file in the directory it
+is run from. In addition, the database only contains information about
+the files, not the files themselves.
+
+This means that database file should probably be kept in the same
+directory (or a directory above) the test files.
+
+
+Setting it Up for the First Time
+--------------------------------
+The sndfile-regtest program should be on your PATH. You can then cd into
+the directory where you intend to keep you test files and
+run the command:
+
+        sndfile-regtest --create-db
+
+which creates a file named '.sndfile-regtest.db' in the current directory.
+
+Files can then be added to the database using the command:
+
+        sndfile-regtest --add-file file1.wav
+
+The --add-file option allows more than one file to be added at a time
+using:
+
+        sndfile-regtest --add-file file1.wav file2.aif .....
+
+
+Checking Files
+--------------
+One or more files that have already been added to the database can be
+checked using:
+
+        sndfile-regtest --check-file file1.wav file2.aif .....
+
+It is also possible to check all files in the database using:
+
+        sndfile-regtest --check-all
+
+
+Running a Regression Test
+-------------------------
+Once you have a collection of files and a database it is possible to test
+new versions of libsndfile before you install them. If for instance you
+have just compiled a new version of libsndfile in the directory
+/usr/src/libsndfile-X.Y.Z, then you can use an existing sndfile-regtest
+binary with the new libsndfile using something like:
+
+    LD_PRELOAD=/usr/src/libsndfile-X.Y.Z/src/.libs/libsndfile.so.X.Y.Z \
+	sndfile-regtest --check-all
+
+
+Reporting Regressions
+---------------------
+Any user who finds a file which was added to the regression database with
+an earlier version of libsndfile and then fails the check with a later
+version of the library should contact the author (erikd at mega dash nerd
+dot com). If possible place the file on a web server and email the author
+a link to it.
+
+