Rewinding the file before passing it to C fixed the problem of not being
able to read the file contents.
Also explain the error about writing to a string.
- Now Guile examples are built in a consistent way to other target
languages.
- Also set GUILE_AUTO_COMPILE=0 to remove auto-compilation is enabled
warnings
Use new guile_embedded_run target or guile_run target for running the
examples like the other target languages (for suppressing stdout if run
from top level).
Consistency with other target language file renames: use runme.scm for
scripts and example.i, example.c for example code.
Add class example to examples being tested.
