[linux-lvm] liblvm2app improvement suggestions

[ben]

When reading the list of logical volumes using the library it can be really 
difficult to determine just what type of volume each one really is. The problem 
is that the attributes field doesn't cover all the possiblities. A volume can 
be an origin and a mirror or it may be a mirror log that is also a mirror. I 
have had to resort to parsing the name string for things like "_mlog" to 
determine what I am dealing with.

It would be really helpful to have some functions like:

lvm_lv_is_snapshot(const lv_t lv)
lvm_lv_is_mirror(const lv_t lv)
lvm_lv_is_origin(const lv_t lv)
lvm_lv_is_mirror_log(const lv_t lv)
lvm_lv_is_mirror_leg(const lv_t lv)

and you get the idea.

Thank you.