Hotfixes

Added **parseKey** option (4th arg) to **distcache_gets()** which enables to parse key(s) as a feature vector format (feature:weight).

The following example is to use only necessary weights in the distributed cache for training.

```sql
use a9a;

set hivevar:modelfile="a9a_model1";
select 
     logress_iter(
        distcache_gets(${modelfile}, features, cast(0 as float), true), 
        label,
        "-total_steps ${total_steps} -eta0 0.095"
     ) as (feature,weight)
  from 
     (select * from a9atrain limit 10) t;
```