Add global option to allow for raw bibtex entries in the reference blocks and cite_detail pages

Removed tag option for raw bibtex entry.
Added a note in the documentation on the usage of this option.

Change test-case to use the global configuration value instead of the tag option for deciding to output the raw bibtex entry.

1. When the raw bibtex entry should be output
2. When Liquid tags inside the bibtex entry should be executed

See #117

See #118

fixes #112

see #108

Add --offset filter option to accompany --max

Details

Fix typo

see #101

add bibtex files to dependency tree

see #84

see #84

fixes #90

Activate jekyll filters

This simple 'solution' returns all entries for ``--max 0``.  Now, to
avoid this the logic of ``offset`` and ``max`` needs to become more
complex - unless I am missing an obvious solution.