Fixed Jinja dependency scanning with dynamic deps

If a Jinja template contains an include or extends with a variable instead
of a constant string, find_referenced_templates yields None for that
dependency. This could cause the dependency scanning algorithm to crash.
Fix sitemap links for sites in subdirectories
Fix for base URLs ending with `/`
Added fix to ignore the current directory
Added doctests
Fixed doctests to work cross-platform
Merge pull request #512 from koniiiik/jinja-dependencies2

Fixed Jinja dependency scanning with dynamic deps
Merge pull request #517 from dhruvbaldawa/fix-sitemap-links

Fix sitemap links for sites in subdirectories
more search form examples (Fix #515)
Added version command, Fix #504
Fix #460
updated translations
add annoying warning when deploying the nikolademo disqus account
flake8 fixes
fixed comment
Fix #508
forgot a set_trace
removed debug print
be a bit less invasive
Make fix for #508 work for empty posts, fixes integration tests