Starting to work on liblsm

[Casey Schaufler]

tl;dr - https://github.com/cschaufler/liblsm.git

I've started to pull together a library for applications that
want to use the new LSM system calls. It's still in a very rough
state, but I wanted to get it in the public eye before I got too
far down a road I might have to abandon. One of its key components
is emulation of lsm_list_modules(), lsm_get_self_attr() and
lsm_set_self_attr() for older kernels. The code lacks much of what
you'd want "production" code to have, like documentation, function
headers and the like. That's coming real soon.

Comments and suggestions for additional interfaces are welcome.