Dashboard: time range can now be read from URL parameters, will override dashboard saved time range, Closes #787, Closes #761

The elasticsearch datasource will now better handle language specifics when making the search partial (ie for search as you type).  This means the search field will now support significantly more complex searches such as:

    title:foo AND title:bar OR baz
    title:mysql AND [3306 TO 3308]
    web~
    title:foo AND -bar

Adding in global search id counter so that async search responses can be discarded if a newer search is being processed.  This prevents older search results from clobbering a newer search that happened to complete faster.

Fixed issue with editing text panel, removed a function from dashboard controller that I though was not used, turned out it was

Small fix to graphite target controller to still revert to text box for expressions with multiple series that do not use a series reference

Templating: Full support for InfluxDB, filter by part of series names, extract series substrings, nested queries, multipe where clauses! Closes #613

Templating: Ability to use template variables for function parameters via custom variable type, can be used as parameter for movingAverage or scaleToSeconds for example, Closes #262

Templating: Interval variable type for time intervals summarize/group by parameter, included auto option, and auto step counts option.
Closes #243

Fixed so white theme looks good with new search and editor panes, Closes #735, and other small fixes and polish