Update instructions for incidents to be updated.

Add HTTP basic authentication option to the PagerDuty configuration
instructions on the README. HTTP basic authentication for PagerDuty
was supported before, as they inherited from same class with JiraClient
Change only the documentation to allow updating incidents on
the PagerDuty.
Merge requests to Jira to get updated issues.

Before this one request was made for all sections in the API configuration
to Jira to get updated issues on the given project and type. Optimize this
by generating a longer JQL with all project and type tuples.
Try to update incidents which are not resolved.

Before that for all incidents found on Jira was sent to the PUT incidents
method on the PagerDuty REST API for updated. It was returning 400
most of the time as al least one of the incidents would not be updated.
Fix this by checking incident status before update.
Do not filter incidents by status.

Log entries were filtered by the status field on the API configuration
by comparing with their incident status. The main purpose for this was
not to create issues for incidents already resolved. Move this logic
to the checker class and remove from the configuration.

This hard-to-understang configuration parameter used for this purpose
before to make the code completely unaware from the incident statuses
on the PagerDuty but the resolved status had to be checked before
trying to update incidents. So there are not any reason now to keep
that parameter on the configuration.