Add variable $vpd containing the viewport camera distance (Fixes #839).
Allow setting $vpt/$vpr/$vpd at top-level to set the viewport camera.
Updated Clipper to 6.1.3a
Some cleanup of old eigen2 workarounds. Added fix to support cameras looking down the Z axis
Link with the correct C++ library on Mac. Added a fix for allowing folder names with regex special characters
#840 Adjust default camera distance after changing FOV to 45 degrees
#840 bugfix: Small axes had wrong rotation, adjusted size of the big axes after changing FOV to 45 degrees
#810 removed unused code
#840 bugfix: Set the up vector to Y axis in the case where we're looking down the Z axis
Merge pull request #841 from openscad/viewport-variables

Add $vpd and make the viewport variables writeable
Added View->View All menu entry
Handle cwd as outputdir
Add test case for issue 835
Resolve #835
Use toString() when generating echo() messages (fixes #838).

When using the Value << operator, strings are encoded (e.g. a newline
character is encoded as \n), but echo() should output the text as given.
Add encoding of \r.
Add support for \x \u and \U escape sequences.

For all escape sequences the 0 byte is illegal and converted to a space.

\x supports only the range from 0x01 to 0x7F as the values greater or
equal to 0x80 could produce illegal UTF-8 sequences.

\u allows to specify unicode codepoints with exactly 4 hex digits.

\U allows to specify unicode codepoints with exactly 6 hex digits.
Handle UTF-8 multi-byte characters in the lexer.
Make concat() a primary feature (not experimental)
Fix no-break space handling.