update test_pystruct
update test_unaligned
update test_varargs_byval
update test_python
update test_structbyval
legalize va_arg on i64/i32*
clarify what we do in le32 v*printf etc. functions
enable benchmark.test_fasta_double to test handling of doubles
add benchmark.test_fasta_double_full, with DOUBLE_MODE=1
use fasta names
do not hope for 64-bit alignment with doubles in DOUBLE_MODE 0 since we will read only 32 bits anyhow
read/write 64-bit aligned doubles directly in le32, when aligned properly