cleaning up viewsingleimage
stream coverurls fixes

* stream coverurl
** no longer setting default coverurl when creating stream, leaving undefined
** setting coverurl to latest uploaded image if not already defined
* gallery
** fixed range default value n bilder_templates.get_html_gallery
   was accidentally hc'd to 3
templates: updated gallery to display more information

* accepts either simple list of img or list of config dict
* displays caption under photo if passed-in
trending - adding site template for consistency
gallery - updating viewallstreams and trending
searchterms - adding initial json service
updated app.yaml to serve static files

useful for:
* css, javascript, etc
* statiac html pages
searchterms - adding keywords function to stream class
searchterms - formatting json for jqueryui autocomplete
adding function to load templates

Functionality:
returns file contents in a string
adding search with autocomplete

* adding plain html template
* updating 'searchallstreams' page
template loader: adding option for jinja template

Functionality:
loads jinja template, does not currently support options for template.render()
autocomplete: filtering results

jqueryui autocomplete widget requires pre-filtering for remote
datasources.
src: http://api.jqueryui.com/autocomplete/#option-source
see "string" or "function"

Bonus: updating option-parsing to be more flexible
autocomplete: "status loading image"

jqueryui autocomplete widget: "loading image" that displays while search
is being retrieved
templates: adding param for jinja template values

Functionality:
values passed in via 'values = {opt:value}' are passed as
template.render(values)
autocomplete template - adding variable for host
app.yaml: updates necessary to deploy

Not completely working yet, javascript doesn't quite work
autocomplete: updated 'minimum length match' to 1

from requirement 'Match on substrings. Minimum length match is 1 char.'
autocomplete: refactor html formatting

Note: in preparation for autocomplete with caching
autocomplete: updating code for remote datasource