fix html escaping in search placeholder text

cgi will not encode '"'.
Add CHANGES for 2.1.0
Remove explicit authorship without significant contributions

Note that there are more unnamed authors with more contributions.
pep8
Fix errors in INSTALLATION.rst
Merge pull request #740 from xi/feature-fix-search-escape

fix html escaping in search placeholder text
pep8
Minor dependencies upgrade
Add .dummy to alembic/versions to make sure directory exists
Add 2.1.1 related changes to CHANGES.txt
Add export create_time to comments and proposals
Add export timezone for metadata.time