Adds tests for the commands:
VimwikiTOC, VimwikiGenerateLinks, VimwikiDiaryGenerateLinks,
VimwikiRebuildTags, VimwikiGenerateTags, VimwikiGoto
Add syntax tests, key mapping tests and table auto format tests.
New helper function in vader setup file.
The default wikis setup in the test vimrc are now mapped to the Docker
containers test user's home directory. The test user does not have
access to write to other locations.
