Establish compatibility with Mono on Linux.

[marnuba]

• Paths now use the correct path separator.
• New Dialog to replace the VisualBasic inputbox, that is not available on Linux.
• Refresh() instead of Invalidate() on Mono to resolve the FPS issues.

[dtremblay]

Missing the InputDialog.resx file - can't commit without it sorry.

[dtremblay]

PR merged into PR34 branch.