Some translations and adding and editing labels 

added purpose
'keep_employees': 'Retener empleados’, 

added some labels

"Sin Comienzo" on years in business
"0" in 


The 0 looks weird in the admin side
![screen shot 2014-09-05 at 11 55 29 am](https://cloud.githubusercontent.com/assets/4454420/4170044/570db5c4-352e-11e4-99c7-2145a6ad70b4.png)


Added some tooltip text
Edited some label text