Use an Open Source implementation of ieee80.c.

CHANGELOG.md

 ## 1.49.1 - (In Development)
 
 *  Vim syntax support for rule files.
+*  Replace `ieee80.c` with the implementation at
+   http://www.realitypixels.com/turk/opensource/ToFromIEEE.c.txt for Debian
+   open source license compliance.
 
 bug fixes:
 

COPYING.IEEE

+Source: http://www.realitypixels.com/turk/opensource/
+
+Open Source Repository
+
+courtesy of
+Ken Turkowski
+
+The source code available from this page may be freely downloaded and used in
+any applications for any purpose, as long as the code is used in its entirety
+and the copyright notice and warranty information is retained.
+
+If you make any improvements to this software, you should provide me with said
+improvements.
+
+If any of this code is incorporated into a commercial product, you should
+notify me of this by email, and provide me with a complimentary copy of said
+product. :-)

Makefile.am

 
 MKDIR=mkdir -p
 
-AM_CFLAGS = -Wall
+AM_CFLAGS = -Wno-endif-labels # Needed to prevent warnings in ieee80.c.
 
 EXTRA_DIST=
 
 src_libespeak_ng_la_CFLAGS = -Isrc/include -Isrc/include/compat \
 	-fPIC -fvisibility=hidden -D _BSD_SOURCE -D_DEFAULT_SOURCE -D _POSIX_C_SOURCE=200112L \
 	-pedantic -fno-exceptions -D PATH_ESPEAK_DATA=\"$(DATADIR)\" -DLIBESPEAK_NG_EXPORT \
-	${PCAUDIOLIB_CFLAGS}
+	${PCAUDIOLIB_CFLAGS} ${AM_CFLAGS}
 
 src_libespeak_ng_la_SOURCES = \
 	src/libespeak-ng/compiledata.c \
 
 src_speak_ng_LDADD   = src/libespeak-ng.la
 src_speak_ng_LDFLAGS = -static -lm ${PCAUDIOLIB_LIBS}
-src_speak_ng_CFLAGS  = -Isrc/libespeak-ng -Isrc/include -D _POSIX_C_SOURCE=200112L
+src_speak_ng_CFLAGS  = -Isrc/libespeak-ng -Isrc/include -D _POSIX_C_SOURCE=200112L ${AM_CFLAGS}
 src_speak_ng_SOURCES = src/speak-ng.c
 
 bin_PROGRAMS += src/espeak-ng
 endif
 
 src_espeak_ng_LDADD   = src/libespeak-ng.la ${PCAUDIOLIB_LIBS}
-src_espeak_ng_CFLAGS  = -Isrc/include
+src_espeak_ng_CFLAGS  = -Isrc/include ${AM_CFLAGS}
 src_espeak_ng_SOURCES = src/espeak-ng.c
 
 ##### phoneme data:

README.md

 
 ## License Information
 
-eSpeak NG Text-to-Speech is released under the [GPL version 3](COPYING) or later license.
+eSpeak NG Text-to-Speech is released under the [GPL version 3](COPYING) or
+later license.
+
+The `ieee80.c` implementation is taken directly from
+[To?FromIEEE.c.txt](http://www.realitypixels.com/turk/opensource/ToFromIEEE.c.txt)
+which has been made available for use in Open Source applications per the
+[license statement](COPYING.IEEE) on http://www.realitypixels.com/turk/opensource/.
+The only modification made to the code is to comment out the `TEST_FP` define
+to make it useable in the eSpeak NG library.