added build directory to ignore list and simplified dir layout

.gitignore

@@ -5,3 +5,4 @@
 *.bak
 *~
 PRIVATE
+build

build_FEM.sh

@@ -16,10 +16,10 @@ if [ ! -d build ]; then
 fi
 cd build
 if [ -d build_FEM ] ; then
-    rm -rf build_FEM
+    rm -rf FEM
 fi
-mkdir build_FEM
-cd build_FEM
+mkdir FEM
+cd FEM
 
 ##
 # CMake call

build_spectral.sh

@@ -15,11 +15,11 @@ if [ ! -d build ]; then
     mkdir build
 fi
 cd build
-if [ -d build_spectral ] ; then
-    rm -rf build_spectral
+if [ -d build ] ; then
+    rm -rf build
 fi
-mkdir build_spectral
-cd build_spectral
+mkdir build
+cd build
 
 ##
 # CMake call
@@ -41,6 +41,6 @@ cmake -D PETSC_DIR=${PETSC_DIR}     \
 
 echo
 echo "Please move to the build directory using"
-echo "    cd build/build_spectral"
+echo "    cd build/spectral"
 echo "Using the following command to build DAMASK spectral solver"
 echo "    make clean all install"