Add menu entry "Reset View" to reset viewport to initial settings (fixes Issue #434).
Merge pull request #529 from t-paul/issue434

Add menu entry "Reset View" to reset viewport to initial settings
Get rid of leading zeros in date tags, causing them to be interpreted as octal in C++
Re-fix: don't add path to empty files. Fixes #536
Fixes #533
download eigen 3 package , eigen2 no longer works
Add support for handling negative step values in ranges (fixes #500).
Add test cases for new range expression handling.
Update 'children' test case using range [4 : -1 : 0] which is now valid.
Fix output of range expressions.
Update 'for' test cases to match the new range expression handling.
Change nbsteps() to uint32_t to make it independent from 32/64-bit platform.
Merge pull request #542 from t-paul/issue500

Allow for statement with negative step value.
Removed eigen2 from build system and documentation. We now require eigen3
Merge branch 'master' into subdivision
improving PRINTDB / PRINTD , chasing down issue #410
further improvement to PRINTD and nef debug output
more debug info
fix a FIXME by eplacing pointers with references
issue 410. rip guts out of CGAL Nef Poly, into nef_helper, prevent crash