Skip fetch and build boost if it already done

Common/3dParty/boost/build.sh

@@ -24,32 +24,30 @@ outputdir="$SCRIPTPATH/boost_1_58_0/build/$platform$arch"
 echo $outputdir
 
 cd "$SCRIPTPATH/boost_1_58_0"
-./bootstrap.sh --with-libraries=filesystem,system,date_time,regex
 
 folder="build/$platform$arch"
-if [ -d $folder ]; then
-  rm -R $folder
-fi
+if [ ! -d $folder ]; then
+  ./bootstrap.sh --with-libraries=filesystem,system,date_time,regex
 
-stage="stage"
-if [ -d $stage ]; then
+   stage="stage"
+   if [ -d $stage ]; then
      rm -R $stage
-fi
+   fi
 
-mkdir -p "$folder"
-mkdir -p "$folder/static"
-mkdir -p "$folder/static_fpic"
-mkdir -p "$folder/shared"
+  mkdir -p "$folder"
+  mkdir -p "$folder/static"
+  mkdir -p "$folder/static_fpic"
+  mkdir -p "$folder/shared"
 
-./b2 --clean
-./bjam link=static
-cp stage/lib/* "$folder/static/"
+  ./b2 --clean
+  ./bjam link=static
+  cp stage/lib/* "$folder/static/"
 
-./b2 --clean
-./bjam link=static cxxflags=-fPIC
-cp stage/lib/* "$folder/static_fpic/"
-
-./b2 --clean
-./bjam link=shared
-cp stage/lib/* "$folder/shared/"
+  ./b2 --clean
+  ./bjam link=static cxxflags=-fPIC
+  cp stage/lib/* "$folder/static_fpic/"
 
+  ./b2 --clean
+  ./bjam link=shared
+  cp stage/lib/* "$folder/shared/"
+fi

Common/3dParty/boost/fetch.sh

@@ -29,7 +29,7 @@ else
 wget http://freefr.dl.sourceforge.net/project/boost/boost/1.58.0/boost_1_58_0.7z
 fi
 
-if [ -d "$SCRIPTPATH/boost" ]; then
+if [ -d "$SCRIPTPATH/boost_1_58_0" ]; then
 echo "boost already extracted"
 else
 if [[ "$platform" == *"linux"* ]]