Take first steps towards integrating new text views.

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branch : new-textviews
Use new text views for the command line.

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branch : new-textviews
Map the bottom margin of the document to the last line when performing hit
tests.

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branch : new-textviews
Implement adjustable tab stops and visible tab indicators.

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branch : new-textviews
Allow for changing the cursor type.

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branch : new-textviews
Clean up text view code.

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branch : new-textviews
Implement call tips for experiemental text views.

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branch : new-textviews
Add an option controlling whether experimental text views are used.

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branch : new-textviews
Closed branch new-textviews

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branch : new-textviews
extra : close : 1
Merge branch new-textviews.