Disabled parallel make in stp build process.

On my system, stp build fails with -j8:

/home/laurent/s2e/build/llvm-native/Release/bin/clang++ -O3 -DNDEBUG -fomit-frame-pointer   -fpic -D __STDC_LIMIT_MACROS -D
__STDC_FORMAT_MACROS -DEXT_HASH_MAP -Wno-deprecated  src/main/main.o lib/libstp.a -o bin/stp
lib/libstp.a(SimplifyingMinisat.o): In function `BEEV::SimplifyingMinisat::solve()':
SimplifyingMinisat.cpp:(.text+0x1a9): undefined reference to `Minisat::Solver::simplify()'

This is not reproducible with -j1. This patch removes parallel make for stp, just to be on the safe side.

Signed-off-by: Laurent Fasnacht <laurent.fasnacht@epfl.ch>
Fixed llvm_version_split in configure scripts to be compatible with python 3

Signed-off-by: Laurent Fasnacht <laurent.fasnacht@epfl.ch>
Python qemu scripts now work with Python 2.6 - 3.2.

Signed-off-by: Laurent Fasnacht <laurent.fasnacht@epfl.ch>
docs: ImageInstallation: fixed path for (native) qemu

Signed-off-by: Laurent Fasnacht <laurent.fasnacht@epfl.ch>