Merge pull request #2601 from karlnapf/develop

some doc updates
Delete tests/integration/tests symlink.

It is outdated since the hierarchy now is testsuite/pythonX-tests.
Merge pull request #2603 from iglesias/develop

Delete tests/integration/tests symlink.
Remove a bunch of math methods in SGVector.
fix half of issues in the KL notebook
Merge pull request #2605 from yorkerlin/develop

fix half of issues in the KL notebook
Merge pull request #2607 from karlnapf/develop

updated to latest wiki
Merge pull request #2604 from iglesias/cleanup_sgvector

Remove a bunch of math methods in SGVector.
some clean ups and data set changes