Fetch char that the current cursor is on.

[imdaveho]

Description: On Unix systems, because the input buffer is not held in memory, there is no way to get the character underneath the cursor on the screen.

Task: Leverage the ScreenCache module on Unix to be able to do this.

Reason: Sometimes you want to toggle the background color of the current cursor location. (eg. to "mark" a cursor for multi cursor edits or to manually create a cursor instead of using the system one). This is not possible unless you can fetch the same char at the cursor location and print it with the new style.

[imdaveho]

Resolved by #4