Convert fs_host files from c back to cpp and style changes.

* fs_darwin.c => fs_darwin.cpp
* fs_freebsd.c => fs_freebsd.cpp
* use bool instead of int again in fs_darwin.cpp (C => C++)
* declare loop varibles inline again in fs_freebsd.cpp (C => C++)
* 2 newlines between top header gaurd and first #include
* 2 newlines after last #include
* freebsd/endian.h and freebsd/regex.h convert \r\n to just \n
* remove some leading tabs in fs_freebsd.cpp
* add newlines after single line if statement in fs_freebsd.cpp
* 80-char limit fixes in fs_freebsd.cpp

Cleanup darwin build system some more.

* Convert fs_darwin.cpp and fs_freebsd.cpp to C.
* Convert extern C calls to __BEGIN_DECLS and __END_DECLS macros
* Link rm_attrs with dynamic libroot

Remove trailing tab

Add fopendir() to fs_darwin.cpp and fix symlinkat().

This completes 2/3 of #8857 and is courtesy of nielx.

Convert fs_host files from c back to cpp and style changes.

* fs_darwin.c => fs_darwin.cpp
* fs_freebsd.c => fs_freebsd.cpp
* use bool instead of int again in fs_darwin.cpp (C => C++)
* declare loop varibles inline again in fs_freebsd.cpp (C => C++)
* 2 newlines between top header gaurd and first #include
* 2 newlines after last #include
* freebsd/endian.h and freebsd/regex.h convert \r\n to just \n
* remove some leading tabs in fs_freebsd.cpp
* add newlines after single line if statement in fs_freebsd.cpp
* 80-char limit fixes in fs_freebsd.cpp

Cleanup darwin build system some more.

* Convert fs_darwin.cpp and fs_freebsd.cpp to C.
* Convert extern C calls to __BEGIN_DECLS and __END_DECLS macros
* Link rm_attrs with dynamic libroot

Remove trailing tab

Add fopendir() to fs_darwin.cpp and fix symlinkat().

This completes 2/3 of #8857 and is courtesy of nielx.