Paste Over Selection Update Screen Issue

Another unrelated issue was found while testing, this time with paste.  The problem occurs when there is a selection, and some text is pasted over the selection, replacing the selected text.  Sometimes, the screen does not update correctly where part of the selection remains.

This can be seen by first copying a single line (some characters followed by a new line) into the clipboard.  Then selecting from the middle of a line to the end of the next non-empty line.  Pasting at this point places the cursor at the beginning of the second, the first character on the second line is removed from the screen, but the rest of the line remains and appears selected.  The document is properly updated as can be seen in the program view.

This problem was corrected by reimplementing the paste function (again).  This time it was given an argument for the clipboard mode with a default of clipboard.  The current text cursor is obtained.  If the cursor has a selection, it is copied into a temporary cursor.  With this temporary cursor, the selection is cleared and the edit box text cursor is set to the temporary cursor to applied the cleared selection.  This may not be the best way to solve this issue, but several other attempts did not work and this solution did.

The selection remains in the origin cursor.  The text is then obtained from the clipboard for the clipboard mode selected and inserted using the original cursor (replacing the selection if there was one).  To also correct the middle-click paste, the insert text call with the current text cursor was replaced with a call to the reimplemented paste function with the clipboard selection mode.

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