style: cpp indentation

[Gedare Bloom]

Hi,

Any guidance on whether we should have a style rule about CPP
directives? Mainly this is for #ifdef #endif guards for conditional
code compilation. There are two options based on what exists in the
cpukit today:

1) Preprocessor directives within indented code should be one nesting
level outside of the affected code.
2) Preprocessor directives within indented code should not be indented.

You can see an example of both, e.g. at
cpukit/score/src/threaddispatch.c:111-132 just to pick one.

-Gedare