[ambrop7]

I learned about the for loop hack from avr-libc[1][2]. It even does some preprocessor abuse to implement different kinds of atomic and non-atomic sections.

[1] http://www.nongnu.org/avr-libc/user-manual/group__util__atom...

[2] http://svn.savannah.nongnu.org/viewvc/trunk/avr-libc/include...