Make fixes for VTK 6

This fixes compilation errors encountered when building PCL
against VTK 6 (from the current git master). The changes are
based on the recommendations in the VTK 6 migration guide [1].

This closes issue #199.

[1] http://www.vtk.org/Wiki/VTK/VTK_6_Migration_Guide
Fix more "Parse error at BOOST_JOIN" when moc-qt4
Add note about PCL_NO_PRECOMPILE when adding a custom ptype

Fixing indention while at it.
Merge branch 'vtk6-fixes' of https://github.com/kylelutz/pcl
patches for VTK 6, QT 5 and VS 2012.