Added secondary indexes

Added msgpack dependency
Merge pull request #41 from euroelessar/master

Added secondary indexes
dnet_log_raw() should use <= for log-level comparison
Always request stats with DNET_ATTR_CNTR_GLOBAL flag set to grab global node's counters
Merge branch 'master' of github.com:reverbrain/elliptics
Added user flags into dnet_io_attr structure - this will be placed into object's metadata.
Added bulk_write overload for data_pointer
Added not_found exception if read zero results
Merge pull request #42 from euroelessar/master

Little changes
Fixed index result assignments
Removed unused function param
v2.22.1.0
Merge branch 'master' of github.com:reverbrain/elliptics
Use std::exeption_ptr() check instead of NULL cast, which is not supported in gcc 4.4
Use auto for iterator testing
Do not use modern for (type &var : container) loop, use old-school iterators, since the former is not supported in gcc 4.4
Do not use modern for (type &var : container) loop, use old-school iterators, since the former is not supported in gcc 4.4
Use system argument list if provided when requesting remote route table
Use correct dnet_copy_addr() error. More debug.
If log levels match, log it