Fix preprocessor indentation

Fix preprocessor indentation

Indent the C preprocessor directives to reflect their nesting
using the following script:

$ cppi -l $(git grep -El '^[[:space:]]*#[[:space:]]*(if|ifdef|ifndef|elif|else|endif|define|pragma)[[:space:]]' |grep -v '\.sh$') |while read f; do
	cppi < "$f" > "$f".cppi; mv "$f".cppi "$f"
done