Final round of Wall fixes for today. If you see any build problem - please contact me.
It works w/o warnings with build_all on pcamsdt1 - but that's only one machine :-) Different compilers may exhibit different warnings/error.

This commit enables Wall for gcc & icc - please report any warnings that are still leftover, with following exceptions:

- Wno-unknown-pragmas is enabled for gcc (until the OpenMP build is fixed)
- Wno-unused-function (cfortran.h defines static functions -- needs to be moved into cfortran.c so we can disable this suppression)
- Wno-write-strings (lots of char* -> const char* conversions need to be applied - Matthew is already working on that)
- Wno-missing-braces (requires boring work in the Tof* classes, which define multi-dimensional arrays w/o any braces except the outer ones... I fixed most, except these).
- Wno-strict-aliasing (to be investigated)

Please note that Werror is NOT enabled (which would turn all warnings into errors) - we should do this after a grace period, when there are
no more warnings left. I don't want to break other peoples builds with cleanups like this.