Addresses #1853, redact session provider secrets

In cases where a database is used for session storage, redact the
session_provider config value. I assumed "@" as the marker for a
database vs file/memory.

Backend configuration: When unknown key was detected the log error was not visible in log file due to logging was initialized after user config file is loaded, logging is now initialized twice, once based on defaults and command line arguments, then then again after user config file, Fixes #1992

Fix minor grammar issue in docs index page

Major refactorings around searching, moved to seperate package, trying to move stuff out of models package, extend search support searching different types of entities and different types of dashboards, #960

Rewriting anb abstracting how dashboards are loaded, unifying db, json files, and script dashboards, #960

Singlestat: threshold checks are now done on a rounded value, rounded to same number of decimals as is shown, Fixes #1983

Conflicts:
	docs/sources/installation/configuration.md
	docs/sources/installation/docker.md

Fixed a series of installation doc issues

1. Set paragraph size to 80 chars for better readability.
2. More formatting fixes.
3. More spelling and grammar fixes.

1. Fixed several spelling and grammar issues.
2. Fixed 404s for the Configuration page.
3. Fixed several Markdown formatting issues.
4. Tidy up of several pages.

Did some jquery flot performance tuning, added text size cache that reduced render times by 25% (for single serie graphs)

Adding Ansible role for Grafana v2.x

Add Android 5 theme colour

Detach stderr in rpm initscript