add chromaprint to optional dependencies

INSTALL.txt

@@ -15,20 +15,24 @@ Before installing Picard, you need to have these:
  * Mutagen 1.20 or newer
    http://code.google.com/p/mutagen/downloads
 
- * python-discid or python-libdiscid (optional)
-   Required for CD lookups.
-   https://python-discid.readthedocs.org/
-   Depends on libdiscid: http://musicbrainz.org/doc/libdiscid
-   Due to slowdowns in reading the CD TOC, using libdiscid versions
-   0.3.0 - 0.4.1 is not recommended.
-
  * gettext
    Windows: http://gnuwin32.sourceforge.net/packages/gettext.htm
 
  * a compiler
    Windows should work with Visual C++ 2008 Express:
    http://go.microsoft.com/?linkid=7729279
 
+ * chromaprint (optional)
+   For fingerprinting (scanning) files
+   http://acoustid.org/chromaprint
+
+ * python-discid or python-libdiscid (optional)
+   Required for CD lookups.
+   https://python-discid.readthedocs.org/
+   Depends on libdiscid: http://musicbrainz.org/doc/libdiscid
+   Due to slowdowns in reading the CD TOC, using libdiscid versions
+   0.3.0 - 0.4.1 is not recommended.
+
 
 On Windows it is recommended to use Pip for Windows:
 https://sites.google.com/site/pydatalog/python/pip-for-windows
@@ -37,7 +41,7 @@ and then just:
   pip install discid
 there for Mutagen and python-discid.
 
-The binaries for Python, GetText (msgfmt) and discid.dll have to be
+The binaries for Python, GetText (msgfmt), fpcalc and discid.dll have to be
 in the %PATH% on Windows.