Fix vs2013 availability of make_reverse_iterator
SHAMap::canonicalize must return a node with the correct ID
Put newly-created nodes in the treeNodeCache
Dispatch incoming TX set data
At level 64, only leaves are allowed
Fetch pack cleanups:
* Limit backed up fetch pack requests
* Cleanups
* Dispatch fetch packs sooner
Make I/O latency available through server_info
Remove redundant checkAccept call
CBase58Data Refactoring:

* Remove unnecessary functions.
* Load from a base_uint const& - don't use void pointers.
* Free comparison functions.
* Explicitly specify encoding alphabet.
* Miscellaneous cleanups.