Description of problem:
Running the command rhevm-config -s VdsRefreshRate=2
sets the value to 2 seconds

I would like to set it accordingly for hours or days in a user-friendly interface
e.x 
rhevm-config -s VdsRefreshRate=1H
Should set the value to 3600 seconds

Version-Release number of selected component (if applicable):
rhevm 3.1 / SI3

How reproducible:
Always

Steps to Reproduce:
1.run the command rhevm-config -s with a specific key
Whereas the default is in seconds, unless a H or D is added after the value

Actual results:
The admin must enter value in seconds

Expected results:
The admin should be able to add value with H for Hours, or D for Days,
And its calculated to seconds, or displayed else than seconds
e.x if its 3600sec it should display 2H
    if its 86,400 it should display 2D

Additional info:
For all Keys, Chars, Sec etc...