This is a board file format change to account for the new properties.
Also, we now only store the critical information about the dimension's
geometry in the board, rather than storing every drawn line.
The DIMENSION object is now an abstract base, and ALIGNED_DIMENSION
is the implementation that exists today (we will add more dimension
types in the future)
Change error displayed when a Library .cpa file is opened (instead of a Layout file)
Add warning if variants exist in original design.
Parse LAYERHEIGHT in LAYER (same thing a MAKE but without the MATERIAL_ID)
Parse PADEXCEPTION in COMPONENT
Add DESIGN as one of the valid UNITS
Loading speed fixed by changing the way CADSTAR_ARCHIVE_PARSER::InsertAttributeAtEnd works (we now have a new attribute in each node to keep track of how many attributes there are). Now loads a 30,000 line file in 10seconds instead of 25 minutes!