Merge pull request #1 from stanislavromanov/master

Optimized code a bit, usinjg linq, converting to var, null exceptions etc..
1.1.0

Cleaned up code some more. Got rid of unnecessary code. Removed Add file
button as well as logic as there is no real use for it. Relabeled Delete
Cell Button to match single Add Folder button.  Changed cell style so
that on load, any invalid references get highlighted. Changed column
width to Fill instead of trying to incorrectly calculate the width.
Added a few comments.
Fixed minor code errors.

Logic was missing to handle invalid folder.
Updated README

Some verbiage changes.
Image added

Visual samples are nice.
Update README.md