(__sread): always read in binary mode
(__swrite): always write in binary mode
* libc/include/stdio.h: no getc/putc macros for cygwin; causes
compatibility issues with different dll versions
* libc/stdio/fopen.c: use __stextmode
* libc/stdio/fdopen.c: ditto
* libc/stdio/freopen.c: ditto
* libc/stdio/findfp.c: set up __SCLE for std{in,out,err}
* libc/stdio/local.h: declare __stextmode
* libc/include/stdio.h (FILE): define __SCLE for "convert line
endings" for Cygwin.
(__sgetc): convert line endings if needed
(__sputc): ditto
* libc/stdio/fdopen.c (_fdopen_r): Remember if we opened in text mode
* libc/stdio/fopen.c (_fopen_r): ditto
* libc/stdio/freopen.c (freopen): ditto
* libc/stdio/fread.c (fread): perform CRLF conversions if __SCLE
* libc/stdio/fvwrite.c (__sfvwrite): ditto
