Added new method to set the metrics for a data source.
Fix merge probs with upstream.
Added new option to specify a metric to be analyzed in command line.
Merge branch 'master' of https://github.com/VizGrimoire/GrimoireLib
Improved Commits queries and CommitsPeriod.
Added opened/ers, changed/ers to trends metrics in ITS.
Improved countries, companies, domains metrics sql.
Merge branch 'master' of https://github.com/VizGrimoire/GrimoireLib
Fixed error in countries and domains get_sql. Missing evol parama.
Fixed connection to MySQL with passwd in R reports.
Added repositories metric for filters.
All metrics lists are now obtained from Data Source API:
    def get_metrics_core_ts()
    def get_metrics_core_trends()
    def get_metrics_core_reports()
Added init_date and last_date for repositorires.
Sync ts and agg data in SCR.
[ds] Shared code for generating metrics between all data sources.
Fixed evolutionary metrics in SCR.
Added metrics config in R section for testing purposes.
[ds] metrics_on now read also from automator config file for all data sources.
Merge remote-tracking branch 'upstream/master'