Implemented work around to EDG 4.7 bug in compiling boost test code (test2013_246.C) and moved default to C language support back to C99 (got dropped to C89 in move from EDG 4.4 to EDG 4.7 by mistake).
Merge remote-tracking branch 'origin/master' into HEAD
(EDG) Install dummy predefined_macros.txt

Install the dummy `predefined_macros.txt` file when the
EDG submodule (source code) is not present.

Fixes this runtime error:

    ```bash
    $ <rose_translator> <input_file>
    Command-line error: invalid EDG_BASE directory:
              /path/to/rose/install/share
    [WARN] Caught frontend exception
    terminate called after throwing an instance of 'rose_exception'
      what():  Errors in Processing: (frontend_failed)
    Aborted
    ```
FIX: made ROSE compile (again) with Boost 1.47 (needs further investigation to move to boost file system 3).