merging fixes from trunk 

git-svn-id: https://svn.mathweb.org/repos/LaTeXML/branches/arXMLiv@3004 2d0c7756-e317-0410-b71c-cbb6040a58f7
 trying to sync SVN with a new Git repo
 trying to resolve my first git conflict
 and adding a README again
gitignore added
 adding Perl ignore rules