Cleaning up lib-src

FileDialog goes into audacity/src/widgets and the mod-* directories go into
audacity/modules.

This leaves nothing in lib-src that isn't a 3rd-party libs or supporting
files.

modules/mod-nyq-bench/images/media-playback-start-small.xpm

@@ -0,0 +1,80 @@
+/* XPM */
+static const char *media_playback_start_small[] = {
+/* columns rows colors chars-per-pixel */
+"16 16 58 1",
+"  c #464745",
+". c #474745",
+"X c #464845",
+"o c #4A4B47",
+"O c #4B4C49",
+"+ c #4C4D4A",
+"@ c #4D4E4B",
+"# c #4E4F4C",
+"$ c #50514E",
+"% c #545551",
+"& c #555754",
+"* c #595B57",
+"= c #5E5F5C",
+"- c #646561",
+"; c #696B67",
+": c #6C6E69",
+"> c #6F716C",
+", c #787A73",
+"< c #797B77",
+"1 c #7E807A",
+"2 c #7F807C",
+"3 c #858781",
+"4 c #898A85",
+"5 c #92958F",
+"6 c #949591",
+"7 c #959592",
+"8 c #959694",
+"9 c #9D9D9A",
+"0 c #A3A4A2",
+"q c #A6A7A4",
+"w c #B0B2AF",
+"e c #B3B5B1",
+"r c #D7DAD3",
+"t c #DCDFDA",
+"y c #DEDEDD",
+"u c #E0E3DE",
+"i c #E1E3DE",
+"p c #E1E4DF",
+"a c #E5E7E3",
+"s c #E6E7E5",
+"d c #E8E8E6",
+"f c #EBEBEA",
+"g c #EBECE9",
+"h c #ECEEEA",
+"j c #EDEEEB",
+"k c #EEEFEC",
+"l c #F2F3F0",
+"z c #F3F3F2",
+"x c #F5F5F4",
+"c c #F6F6F5",
+"v c #F6F7F6",
+"b c #F9F9F9",
+"n c #F9FAF9",
+"m c #FAFAF9",
+"M c #FAFBFA",
+"N c #FBFBFA",
+"B c #FBFBFB",
+"V c None",
+/* pixels */
+"VVVVVVVVVVVVVVVV",
+"VVVVVVVVVVVVVVVV",
+"VVV VVVVVVVVVVVV",
+"VVV++oVVVVVVVVVV",
+"VVVOBw+ VVVVVVVV",
+"VVV#Bls0$XVVVVVV",
+"VVV%BcBBy9&VVVVV",
+"VVV*Bhhkhhs8:VVV",
+"VVV=Bpuuacf71VVV",
+"VVV-Brtcz7>VVVVV",
+"VVV;BxBq<VVVVVVV",
+"VVV>Be36VVVVVVVV",
+"VVV,41VVVVVVVVVV",
+"VVV>VVVVVVVVVVVV",
+"VVVVVVVVVVVVVVVV",
+"VVVVVVVVVVVVVVVV"
+};