Add status types and implement transfers-limit

For all status types, we should define an explicit data format. The
purpose of this format is to allow different front ends to render the
output. The status types currently defined live in
riak_core_status_types.hrl.

The generic parser of status types lives in riak_core_status:parse/3.
The specific callback functions that do the actual formatting of the
output for the console live in riak_core_console_writer. The functions
riak_core_console:transfers_limit/{0,1} actually use the writer and
print the output for the new implementation of
`riak-admin transfers limit [Node]`.

Additionally add autosizing to riak_core_console_table

When calling riak_core_console_table:print/2 without a spec including
sizes, the table elements will be sized according to the maximum length
of element in each row. If that all fits within the console width,
including borders, then it is printed. If it does not fit, the elements
are reduced in size until everything fits on screen. If the console
width is not detected with io:columns() then the default value,
?MAX_LINE_LEN=100 is used instead.
Reformatting and minor dialyzer fixes.
Indentation
Refactor out determine_max_line_length function.
Better spec for all_active_transfers.
Use cluster metadata to get/set transfer limits

riak_core_handoff_manager now uses cluster metadata to get and set
transfer limits per node. The configuration in the file overwrites the
current cluster metadata value for that node on startup of the handoff
manager. All sets still use RPC calls to the given node, but then add
them to cluster metadata instead of changing the configured environment
variable. The environment variable now always matches what was in the
config file at node startup.
Add rpc versions of transfer limit

Add backend calls for `riak-admin transfers limit` that use rpc like the
old version of `riak-admin transfer-limit`. The versions intended to be
used without a flag use cluster metadata for efficiency.
New CLI -  riak-admin handoff limit <action> <value>

 * Flag `--node` will operate on the given node
 * Without passing `--node` all nodes operated upon
 * `riak-admin handoff` lists subcommmands (limit only for now)
 * `riak-admin handoff limit` shows usage for limit subcommand
 * Add rpc versions of `riak-admin handoff limit --show` when using
   --force-rpc option.
Fix comment formatting (double-% FTW)
Merge pull request #640 from basho/feature/dtr/handoff-new-cli-1237

New CLI -  riak-admin handoff limit

Reviewed-by: macintux
Merge pull request #637 from basho/feature/metadata-backed-transfer-limits

Use cluster metadata to get/set transfer limits

Reviewed-by: macintux
Merge pull request #635 from basho/feature/status-types

Add status types and implement transfers-limit

Reviewed-by: macintux