Fixed a segmatation fault with rle

Length in while should be len - 1. Need to check with image data.
Length variable is actual_len + 1, don't know why for the hand coded file data.
Addressed special chars cornet case

When ever special char occurs, we shall replace it with value close to it.
This way, we can make sure that the output len is always less than input length.
Colori is anyway can't be differentiated from colori - 1;
Decreasing ESC char - replacing char difference