Fix compile error under windows (issue #14)
Merge branch 'fixVS2010CompileErrors'

* fixVS2010CompileErrors:
  Fix compile error under windows (issue #14)
Add widget export to vtk button manager (issue #14)
Merge branch 'fixVS10LinkErrors'

* fixVS10LinkErrors:
  Add widget export to vtk button manager (issue #14)