Adjust bootstrap for current B2 builds.

These are some minor adjustments to the bootstrap step of building B2. For bootstrap.sh we no longer shove B2 build output to the bootstrap.log file as we want to see the helpful diagnostic messages from B2. For example, indicating the requirement of C++11 for the engine build. This also renames from Boost.Build to B2.

bootstrap.sh

@@ -1,5 +1,5 @@
 #!/bin/sh
-# Copyright 2019 Rene Rivera
+# Copyright 2019-2020 Rene Rivera
 # Copyright (C) 2005, 2006 Douglas Gregor.
 # Copyright (C) 2006 The Trustees of Indiana University
 #
@@ -152,7 +152,7 @@ Configuration:
   -h, --help                display this help and exit
   --with-bjam=BJAM          use existing Boost.Jam executable (bjam)
                             [automatically built]
-  --with-toolset=TOOLSET    use specific Boost.Build toolset
+  --with-toolset=TOOLSET    use specific B2 toolset
                             [automatically detected]
   --show-libraries          show the set of libraries that require build
                             and installation steps (i.e., those libraries
@@ -212,7 +212,7 @@ if test "x$TOOLSET" = x; then
     ;;
     
     * )
-    # Not supported by Boost.Build
+    # Not supported by B2
     ;;
   esac
 fi
@@ -221,13 +221,12 @@ rm -f config.log
 
 # Build bjam
 if test "x$BJAM" = x; then
-  $ECHO -n "Building Boost.Build engine with toolset $TOOLSET... "
+  $ECHO "Building B2 engine.."
   pwd=`pwd`
-  (cd "$my_dir/tools/build/src/engine" && ./build.sh "$TOOLSET") > bootstrap.log 2>&1
+  (cd "$my_dir/tools/build/src/engine" && ./build.sh)
   if [ $? -ne 0 ]; then
       echo
-      echo "Failed to build Boost.Build build engine" 
-      echo "Consult 'bootstrap.log' for more details"
+      echo "Failed to build B2 build engine"
       exit 1
   fi
   cd "$pwd"
@@ -327,14 +326,14 @@ if test -r "project-config.jam"; then
     counter=`expr $counter + 1`
   done
 
-  echo "Backing up existing Boost.Build configuration in project-config.jam.$counter"
+  echo "Backing up existing B2 configuration in project-config.jam.$counter"
   mv "project-config.jam" "project-config.jam.$counter"
 fi
 
 # Generate user-config.jam
-echo "Generating Boost.Build configuration in project-config.jam for $TOOLSET..."
+echo "Generating B2 configuration in project-config.jam for $TOOLSET..."
 cat > project-config.jam <<EOF
-# Boost.Build Configuration
+# B2 Configuration
 # Automatically generated by bootstrap.sh
 
 import option ;
@@ -410,7 +409,7 @@ Further information:
    - Getting started guide: 
      http://www.boost.org/more/getting_started/unix-variants.html
      
-   - Boost.Build documentation:
+   - B2 documentation:
      http://www.boost.org/build/
 
 EOF