replaces double quotes by simple quotes for facilitating search
improves documentation of configuration
removes useless code that hinders understandability
cleans the repo
adds the documentation of bibtexbrowser to the Git repository
updates the documentation for correct rendering on Github
adds a word about pull requests on documentation
Fixes a potential cross site scripting (XSS) issue
Merge pull request #16 from arnehaber/clean_xss_fix

Fixes a potential cross site scripting (XSS) issue
improves the configurability of the output through CSS classes (adds .bibmenu and .bibanchor)
preserves math formula for use with MathJax (bug reported by Elvis)
fixes a bug in Javascript progressive enhancement (bug reported by Elvis)
improves the configurability of the output through CSS classes (adds .bibcomment)
improves the configurability of the link menu ([bib], [pdf], ...)
adds support for "file" fields (exported by Zotero)

suggested by Luis J. Villanueva, see https://github.com/monperrus/bibtexbrowser/pull/14
adds a link to the github page
merged from upstream