* device/include/pic16/usart.h: added, missing in previous commit,

* device/include/pic16/usart.h: added, missing in previous commit,
* device/include/pic16/adc.h: fixed typo,
* device/lib/pic16/libc/utils/cvtdec.S: added missing in previous
commit,
* device/lib/pic16/libc/stdlib/g_ftoa.S: modified to include
<p18fxxx.inc>
* device/lib/pic16/libc/stdio/streams.c: leave stdin, stdout
uninitialized because a bug appears with gplink
* device/lib/pic16/{some makefiles}: moved $(CSTD) from CFLAGS to
COMPILE_FLAGS and added CPPFLAGS with -nostdinc because sdcpp
complains for unrecognised option

git-svn-id: https://sdcc.svn.sourceforge.net/svnroot/sdcc/trunk/sdcc@3718 4a8a32a2-be11-0410-ad9d-d568d2c75423