rm dead comment code
rename ajax overlays to url overlays
introduce jsUri

I used a [fork by Denis Sokolov](https://github.com/SlikNL/jsUri/)
and used uglify-js to minify it.

We decided against [URI.js](https://github.com/medialize/URI.js)
because it is too large.
improve setting format to .overlay in overlay urls
trigger overlay on pageload
validate overlay path
manipulate addressbar when overlay state changes
error message for non-js users
Allow keyword arguments in input form helper
Work around NoneType error in build.sh:bootstrap (Fixes #522)
Fix html errors in milestone edit form
Merge pull request #555 from xi/feature-553-link-to-overlays

Feature 553 link to overlays
fix overlay mask
Allow badges to impact mixed sorting (fixes #365) (NOTE: Reindex solr!)

This adds a new integer field to all badges. In special sorting methods
(currently only in the mixed proposal sorting method), this field is
used as the first level sort key, i.e. badges with higher impact value
are always put on top of badges with lower impact values.

At a later stage, a mixed sorting method for users and instances can
easily be implemented as well, e.g. using impact as first level sort key
and then activity.

This is implemented by normalizing the "base mixed score" to -pi/2 to
pi/2 using arctangent, and then adding (impact * pi). An alternative way
would be to add impact directly into solr and use multiple sort_by
methods in sequence.

NOTE: As the score calculation has changed, the solr index has to be rebuilt for all proposals:

    bin/paster index INDEX proposal -c etc/adhocracy.ini
    bin/paster index DROP proposal -c etc/adhocracy.ini
Merge pull request #506 from xi/feature-remove-dead-comment-template

rm dead comment code
Merge pull request #558 from nidico/feature-365-sort-effect-badges

Allow badges to impact mixed sorting (fixes #365) (NOTE: Reindex solr!)
Allow badge deletion (fixes #105)

This allows to delete the different kinds of badges from the badge
overview.
Merge pull request #499 from nidico/feature-105-delete-badges

Add badge deletion to UI (fixes #105)
fixup 414431e for old browsers without history api
Remove unneeded template variable

Fixup f3e57abf0c0b9c7b3b611ea79090a6e3f9de3ad5