_cat/recovery should report translog replay progress

[pickypg]

_cat/recovery and _recovery should record the translog progress (percentage or otherwise) in terms of how much phase 3 of recovery has been processed.

For large shards, it can be painful watch automatic relocation's like:

my-index-2015-04-10 47    3053258  replica    translog NODE-SOURCE NODE-TARGET n/a        n/a      352   100.0%        20911663130 100.0%

The translog is ~20 GB in this example, so it's very hard to guess how long I will have to wait until it finishes replaying it on the target node.

[ppf2]

May be related to #10042

[pickypg]

Yep! Didn't see that this made it into 1.5. The above was running 1.4.4.