Use Undo and Redo commands with WordWrap enabled

[luizfernandonb]

Is your feature request related to a problem? Please describe.
No, it's just a feature, which in this case would be to be able to use Undo and Redo commands with WordWrap activated in a TextView.

[luizfernandonb]

@BDisp, @tig i believe this PR of yours has broken some parts of the TextView, a text file loaded using LoadFile() doesn't even load

Also when you add enough characters for a line break to occur, an extra space is embedded at the end of the first line:

And when we try to erase some characters, an exception is thrown (The text is not even erased):

[BDisp]

I think is better to reopen this issue or create a new one. I confirm this bugs and I'll try to fix them.

[luizfernandonb]

@tig, can you reopen this issue please?

[BDisp]

Also when you add enough characters for a line break to occur, an extra space is embedded at the end of the first line

The extra space at the end of a line is for allows the cursor stay visible, otherwise the user can have some difficult to discover on what position he is in the text.