Customize table/grid layout in Tree view for better display of long file names.

Prior to this change, long strings in the Name column would either overlap text in the Message column or else wrap within the column and overlap the following Name (depending on whether the Name included a break character like ' ' or '-'). This CSS-only change tweaks the table layout to give more room to the Name/Message columns, prevent wrapping of text in the Name column, and enable ellipsis ('…') for truncated text.
Switch RepositoryCommitModel to use Commit.Message instead of Commit.MessageShort so the complete text of the commit message will be available in the Commits and Commit views.

Note: Commit.Message includes embedded '\n' characters as-is; this change does not attempt to translate them to line-breaks (ex: via "<br/>").
Merge pull request #68 from DavidAnson/messageshort

Switch RepositoryCommitModel to use Commit.Message instead of Commit.Mes...
Merge pull request #67 from DavidAnson/ellipsis

Customize table/grid layout in Tree view for better display of long file...