When building Boost, stop on first error by default.

[SVN r57990]

bootstrap.bat

@@ -32,7 +32,12 @@ REM export BOOST_JAM_TOOLSET, and I don't know how to do that
 REM properly. Default to msvc for now.
 set toolset=msvc
 
-ECHO using %toolset% ; > project-config.jam
+ECHO import option ; > project-config.jam
+ECHO. >> project-config.jam
+ECHO using %toolset% ; >> project-config.jam
+ECHO. >> project-config.jam
+ECHO option.set keep-going : false ; >> project-config.jam
+ECHO. >> project-config.jam
 
 ECHO.
 ECHO Bootstrapping is done. To build, run:

bootstrap.sh

@@ -373,6 +373,9 @@ option.set prefix : $PREFIX ;
 option.set exec-prefix : $EPREFIX ;
 option.set libdir : $LIBDIR ;
 option.set includedir : $INCLUDEDIR ;
+
+# Stop on first error
+option.set keep-going : false ;
 EOF
 
 cat << EOF