Add time attribute to individual datasets in TimeSeriesHDF5
Re-enable and fix VTK6 build
Fix plotting with VTK6.

Remaining bug: The scalar-bar is sometimes placed outside the viewport.
This appears more often on 6.0 than on 6.1, and looks like a VTK bug.
Fix cut-n-paste typo in VTK5 build
Make the VTK5/VTK6 build configurations as similar as possible.

Tested with VTK 5.8 and 6.
Fix building of demos outside DOLFIN build directory with VTK6.
Second attempt at fixing outside-build-dir building with VTK6
Fix VTK link libraries for demo_plot-qt
Clean up vtk linking for external builds
Apply insert to vector reads
Replacing vector clear() with swap() such that memory is freed when cleaning mesh topology connections.
Fix typo in ChangeLog
Merge branch 'mikael-mortensen/swap4clear-connectivity'
Merge branch 'chris/fix-issue-181'
Merge remote-tracking branch 'origin/chris/fix-issue-171'
Merge branch 'jobh/fix-issue-149'

Updates to work with VTK6.