doc: clean up isl_val documentation

Some unary operations were mistakenly listed under the binary operations.

Signed-off-by: Sven Verdoolaege <skimo@kotnet.org>
doc: update isl_*_list documentation

We missed this in 3e27dfa (declare isl_*_list together with isl_*,
Wed Mar 27 12:09:23 2013 +0100).

Signed-off-by: Sven Verdoolaege <skimo@kotnet.org>
document isl_set_is_singleton

Signed-off-by: Sven Verdoolaege <skimo@kotnet.org>
doc: fix typos

Signed-off-by: Sven Verdoolaege <skimo@kotnet.org>