Fixed columns need support align by right

[chinawsb]

In modern grid like html,fixed columns can be at both side, current version virtualtreeview only support fixed columns at left,I sugguest support this in new version.

[chinawsb]

I have create a solution for this function .

1. Add coFixedOnTail for column option.
2. Add poDrawFixedOnTail for internal paint options.
3. Add patch code make take a effect.

Known issues

1. This is not a offical solution.
2. Only support left to right layout.
3. Tree content paint not update sync with right fixed column header resizing.
4. Scroll content blink in right fixed column content.

patch.zip

[chinawsb]

In the patch file,changed code is marked by swish patch.

[joachimmarder]

@chinawsb : Any chance that you provide a pull request or create a real patch file?