Re: [Libguestfs] enabling more syntax-checks

The first c-set cleans up the list of excluded syntax-checks. The second enables the sc_avoid_ctype_macros test and changes each use of a ctype macro like isspace to c_isspace. This makes it so such tests (often parsing-related) is locale-independent. Otherwise, in some odd corner cases (combination of non-C locale and perverted inputs), I suspect that libguestfs tools would mistakenly accept surprising inputs.