[ofw] [PATCH] etc: add generic linux compatibility code

[Sean Hefty]

>To support the porting of OFED code, such as the infiniband-diags, provide a
>set of linux compatible include files and functions.
>
>This adds a set of header files under inc/user/linux so #include statements
>in code will find them.  In some cases, the header files are blank, but in
>others, they contain mappings between the linux calls and equivalent windows
>calls.
>
>Where more complex functionality is needed, source files are added under
>etc/user to provide it, similar to what was done for getopt.
>
>These headers and source files are used to support the OFED infiniband-diags
>in the WinOF build environment.

Unless there's an objection, I will begin committing these changes to the trunk
starting tomorrow (2/27).

Thanks,
- Sean