New autoconf macros:

SAH_CHECK_LIB:  Like AC_CHECK_LIB(), except it checks STATIC_LIB_LIST
for libraries that should be linked statically.  Static libraries are attempted
to be linked with fully qualified path.  If that fails, the static flags
(-Wl,-Bstatic) are used.  If no static library is found, the library is linked
dynamically.

SAH_STATICIZE_LDFLAGS:  Goes through a given set of LDFLAGS and determines with
libraries should be linked statically based upon STATIC_LIB_LIST, then calls
SAH_CHECK_LIB on every library.

SAH_DEFAULT_BITNESS:  On architectures that support both 32 and 64 bit
executables, this determines the current default model (including any CFLAGS
settings).

SAH_OPTION_BITNESS:  Sets up a configure option to set the compiler -m64 or -m32
(or equivalent) flags for 32/64 bit compilation.

svn path=/trunk/boinc/; revision=5957