Minor enhancement/fix for mc.ext

[mnk]

Concerning objects/libs:
right now:
# Object
type/^{ELF
<------>#Open=%var{PAGER:more} %f
<------>View=%view{ascii} file %f && nm %f}

# Manual page
# Exception - .so libraries are not manual pages
regex/\.(so|so\.[0-9\.]*)$
<------>View=%view{ascii} file %f && nm %f

What's wrong with it:
in that file top has priority over bottom,
so the second case is never hit (at least on Linux);
also, if shared lib is stripped, no symbols will be reported;

Proposed change:
# Manual page
# Exception - .so libraries are not manual pages
regex/\.(so|so\.[0-9\.]*)$
<------>View=%view{ascii} file %f && nm -C -D %f

# Object
type/^{ELF
<------>#Open=%var{PAGER:more} %f
<------>View=%view{ascii} file %f && nm -C %f}

(demangling as a bonus)