First version with integrated citeproc-js

Must stabalized, but works. The js-directory has been reorganized in
order to integrate citeproc-js seamlessly.
UI-choreography now includes the just included citation style drop-down box
The citation feature starts beeing usable

References ([x] where x is a natural number) are now placed into the text and citations are inserted accordingly.
Minor changes
[new feature] reference insertion only after words

the implementation is still buggy and must be enhanced, nonetheless, the
approach seems to work.
[bugfixes, coderefactoring] Insertion of references enhanced
[bugfix] supress the printing of 'undefined'

When there is a lack of information in the hidden input fields, no
longer "undefined" is prited in the references. It is replaced by an
empty string.
[feature] URLs in references are hyperlinks now
[feature] insert a reference into citationarea is now prohibited.
[bug] corrected pathinformation

Hitherto the path to some files was hardcoded. now, only the path within
the plugins folder is hardcoded and the remaining part is delivered by
wordpress. Hence, the plugin path (which can be freely determined by the
wp administrator) can deviate compared to the default.
[bug] deleting of entries confused the reference numbers

The reason for this bahavior is caused by some weird transformations
performed by tinyMCE. Using the <p>-tag instead of the <div>-tag solves
this problem.
[feature] reflecting the searchquery

A field has been added, that reflects the search query for the user.
[feature] "get recommendations"-button added to WYSIWYG-editor

A custom "get recommendations"-button has been added to the tinyMCE.
[feature] Citationmarker

If a citation has already been used in the text, it is marked
accordingly.
[feature] Handling for multiple insertion of same resource added

A handling for the insertion of the same resource more than once has
been added. Such entries are highlighted with a slighly different color
and, when the user pushed the "add" button, he will be told that the
entry he wants to add has already been added. The user can decide if
he/she wants to continue or stop the insertion.
[bug] Insertion into citations area hindered

There was a case when the user could insert a reference into the citation
area, which is not intended. This case now corrected.
Merge branch 'dev' into mergeUniPassauChanges

Conflicts:
	eexcess-functionality.php
Merge pull request #3 from n-witt/master

citeproc-js integration