See buildingSMART#341

As discussed in the meeting, the `ProjectId` is required

Merge pull request buildingSMART#127 from BuildingSMART/feature/viewp…

…ointDescription

Adapt components description from BCF API

Merge pull request buildingSMART#85 from BuildingSMART/bcf-2-1-viewpo…

…ints

BCF 2.1: Update xml schema for viewpoints

Merge pull request buildingSMART#46 from pasi-paasiala/master

Improved documentation for root and markup

add Guid to component

Visinfo.xsd; add Bitmap/Height