- for proto better use simple seq. allocation without using meta-sequence which is...

- for proto better use simple seq. allocation without using meta-sequence which is going to improve later;
- implement simple ll_fid_alloc() which allocates new fids on client;
- implemented simple ll_fid2ino() which allocates client inode numbers from passed fid;

- root object is allocated in separate sequence with number 1. Sequences and fid numbers with value 0 are not allowed by ldlm - fixing that. First seq is 1, first fid in seq is 1;

- implemented simple mdt_alloc_seq() which allocates new sequences to clients;
- fixes in mdt_init_seq();
- using sema instead of spinlock in mdt_alloc_seq(), as bumping the seq and saving it to back store should be atomic operation and sleeping on possible IO with lcoked spin lock is not allowed.