Apple macOS ARM support

[lfoppiano]

This PR add some modifications to support the apple macOS ARM processors. I've added also the -nc flag in wget so that it avoid re-downloading the same files if the local is already present

Below I did some tests with the x86_64 and arm versions:

Run	ARM	INTEL
1	0m4.295s	0m4.563s
2	0m4.307s	0m4.550s
3	0m4.262s	0m4.565s
4	0m4.335s	0m4.584s
5	0m4.301s	0m4.644s
6	0m4.328s	0m4.574s
7	0m4.355s	0m4.538s
8	0m4.353s	0m4.613s
9	0m4.318s	0m4.580s
10	0m4.346s	0m4.675s

Log below:

(base) Lucas-M1-MacBook-Pro:pdfalto lfoppiano$ for x in `seq 1 10`; do echo "ARM"; time mac_arm-64/pdfalto /Users/lfoppiano/Downloads/Almonds_Guide_First_Year_2022.pdf ~/Downloads/bao.xml; echo "INTEL"; time mac-64/pdfalto /Users/lfoppiano/Downloads/Almonds_Guide_First_Year_2022.pdf ~/Downloads/bao.xml; done

ARM
real    0m4.295s
user    0m4.232s
sys 0m0.054s

INTEL

real    0m4.563s
user    0m4.457s
sys 0m0.089s

ARM

real    0m4.307s
user    0m4.238s
sys 0m0.052s

INTEL

real    0m4.550s
user    0m4.446s
sys 0m0.090s

ARM

real    0m4.262s
user    0m4.211s
sys 0m0.045s

INTEL

real    0m4.565s
user    0m4.470s
sys 0m0.086s

ARM

real    0m4.335s
user    0m4.265s
sys 0m0.058s

INTEL

real    0m4.584s
user    0m4.470s
sys 0m0.092s

ARM

real    0m4.301s
user    0m4.242s
sys 0m0.051s

INTEL

real    0m4.644s
user    0m4.518s
sys 0m0.099s

ARM

real    0m4.328s
user    0m4.252s
sys 0m0.063s

INTEL

real    0m4.574s
user    0m4.464s
sys 0m0.095s

ARM

real    0m4.355s
user    0m4.275s
sys 0m0.057s

INTEL

real    0m4.538s
user    0m4.441s
sys 0m0.088s

ARM

real    0m4.353s
user    0m4.285s
sys 0m0.054s

INTEL

real    0m4.613s
user    0m4.497s
sys 0m0.098s

ARM

real    0m4.318s
user    0m4.256s
sys 0m0.055s

INTEL

real    0m4.580s
user    0m4.476s
sys 0m0.092s

ARM

real    0m4.346s
user    0m4.268s
sys 0m0.061s

INTEL

real    0m4.675s
user    0m4.530s
sys 0m0.112s