TextIter must not be reused in between buffer changes. This resulted in
unpredictable behavior when using search and replace. For instance,
in the following string:
This _is_ a _test_ of _search_ and _replace_
Searching for "_" and replacing with "**" sequentially would:
[0] This **is_ a _test_
[1] This ****is a _test_
[2] This ****is a **test_
[2] This ****is a ****test
Replace had similar results.
Changes include:
* Much better encapsulation of textview/textbuffer, with each isolated
responsibility living independently on its own class/file.
* Less code overall
* Various small fixes around the components involved, such as:
* Indentation of nested lists (fixes#120)
* Unwanted scroll on select all (ctrl+a)
* Removal of unused code around the components involved
* Fixes for scrollbar location, now at the edge of the window
Gonçalo Silva