strtof() is faster than strtod(), see:
http://www.gnu.org/software/libc/manual/html_node/Parsing-of-Floats.html
"(...) strtof can be substantially faster than strtod, but has less precision"
strtof() was added in C99 so BUILD_STRICT_C90 must be disabled to have any
chance to use it (MSVC does not provide strtof(), GCC does).