#326 BufferTabs with fix width

[drvdrv]

It would be nice if BufferTabs could handle "fix tab width".
I usually work on a lot of file and I prefer to use tabs on the left side.
But when new file is opened which is longer than the opened ones the left sied is resized.
It is even worst when a file has a long name.

Proposal:
In the plugin options add a new part:
checkbox: "fix with"
- long file name (two edit box) i.e.: [10]...[5]
in this case the file name is 18 char long and changed in the tab: "very_longlonglonglong_file.txt" => "very_longl...e.txt"
- short file name (three radio box) i.e.: align left, middel, right
in this case the file name is changed in the tab: "short.txt" => " short.txt " (it is also 18 char long)

Thanks in advance and I hope it will be accepted.