More edge cases.

Fixed reading imported statistics for weekly, monthly, and yearly per…

…iods.

Fixed sample factor for imported statistics.

Added search field for imported statistics.

Fixed storing bot traffic reason.

Added reason for bot traffic, updated dependencies.

Merge pull request pirsch-analytics#325 from pirsch-analytics/v6.12

v6.12

Fixed funnel starting without visitors.

Fixed division by zero.

Updated dependencies.