Convert all tabs to spaces

[terrelln]

Generated with the following command and manually checked:

sed -i '' $'s/\t/    /g' lib/**/*.{h,c} programs/**/*.{h,c} tests/**/*.c contrib/**/*.{h,c} examples/**/*.c zlibWrapper/**/*.{h,c}

[Cyan4973]

Welcomed improvement @terrelln !

we have now a generic method to clean these accidental tabs.
I consider to make it part of make all.