Merge topic branch t/sf_float into master

A single patch which adds two new sample formats for 32 bit IEEE
float waveform data. Cooking for two months.

* refs/heads/t/sf_float:
  New audio formats: 32 bit float (little and big endian).

diff --cc NEWS.md
index 0886b26e2a31eb6af6e12103a77fac3ed11afdbc,935e8493cedeb4c3c94ffafbb4c6d11035ea65f4..a60878fbf9b2634f0318637df1ec5c48ebfd5093
--- 1/NEWS.md
--- 2/NEWS.md
+++ b/NEWS.md
@@@ -15,6 -13,6 +15,7 @@@ NEW
  - The chunk table and mbox listing modes of the ls server command
    have been deprecated. They still work, but a warning is issued to
    inform the user about the deprecated option.
++- The alsa writer also supports 32 bit float sample formats.
  
  Downloads:
  [tarball](./releases/paraslash-git.tar.xz)