Added flag -mno-avx to tackle assembler errors during compiling on some new Intel core processors
Merge pull request #101 from ToMadoRe/hydro-devel

The describtion is actually not right. This PR just adds `${CMAKE_CXX_FLAGS}` to the line `set(CMAKE_CXX_FLAGS "-O4 -Wall -fPIC -std=c++0x")` which can't do any harm but prevents overwriting the previously set flags.