Added <macro name="substitute-title"> for unsigned articles

Added <macro name="substitute-title"> to cope with unsigned articles and reviews, where the name of the newspaper or periodical (=container-title) needs to stand in place of the author (see CMoS 14.207 and 14.217).
Create medienwandel-medienwechsel-medienwissen-chronos.csl
Update and rename medienwandel-medienwechsel-medienwissen-chronos.csl to nccr-mediality-chronos.csl

Change of names
Create helsinki-theology

Added a style from Helsinki University's Faculty of Theology
Shorter version of "substitute-title" macro

Now that pandoc-citeproc has been fixed (see https://github.com/jgm/pandoc-citeproc/issues/58), this shorter version of the "substitute-title" macro works in pandoc, too.
Create revista-fave-seccion-agrarias.csl
Rename revista-fave-seccion-agrarias.csl to revista-fave-seccion-ciencias-agrarias.csl
Update and rename revista-fave-seccion-ciencias-agrarias.csl to revista-fave.csl

The default locale has been changed from "es" to "es-ES", the missing accent in the title has been corrected and the filename, id and self have been shortened properly.
Renamed file and changed links.
Update and rename revista-fave.csl to revista-fave-seccion-ciencias-agrarias.csl
PMC-21028 - potential fix for MLA style

PMC-21028 - squash
added <text macro="title"/> to "substitute-title" macro
Implement @rmzelle's fix instead of mine
Fix prefixes and suffixes for MLA; include changes in MLA-with-url
Merge pull request #1083 from Klortho/master

Potential fix for MLA style; question about `source` variable
Moved <text macro="title"/>
Merge pull request #1028 from nickbart1980/master

<macro name="substitute-title"> for unsigned articles
Merge pull request #1085 from citation-style-language/remove-unused-macros

Delete unused macros (except for CMoS styles)
add DOIs to Elsvier Vancouver and allow URLs for webpages and blogpost. Linking to a different set of instructions ("Energy")vthat call for both and seem more generic
Merge pull request #1074 from alexo81/patch-1

Create revista-fave-seccion-ciencias-agrarias.csl