Stackalytics deployment clean up

* Scripts and conf locations are set in setup.cfg
* Flask-styled is replaced by oslo config
* Scripts from bin are replaced by one generated by entry_points

Change-Id: I26620b8d945d331b2d5abebce41ca177f3e93571
Several clean-ups related to config handling

* Check and create folder for repo sources
* Refactored vcs not to access sources_root config param directly
* Fixed dashboard to call update only once per request
* Removed unused parameters from config

Fixes bug 1201792

Change-Id: I455c43fdc17072ffcade502771c292e5c84d6cd7
Location of sources folder is changed to /var/local/stackalytics

Change-Id: I8dd0eae994a5701d28035819c96d14d42e2af96f