JENKINS-21600: Implement lazy loading of HistoryDescr in preparation for pagination.
JENKINS-21600: Refactor lazy loading.
Yordan added as developer
JENKINS-21600: Config entry for max history entries per site
jobconfighistorytest fixed
Renaming ...PerPage instead  ..PerSite
Remove useless parenthesis.
Missing change
JENKINS-21600: Restrict number of returned values to maxEntriesPerPage
JENKINS-21600: When less configs are stored then maxEntriesPerPage return all entries.
Reduce visibility as these methods are only meant to be accessed
in tests.
JENKINS-21411 Shift (Prev/Next) for diff results

Both sides goes to the next or previous entry (shift)
Checkstyle
PMD
Bad optimization changed
JENKINS-21411 Shift (Prev/Next) for diff results for slaves
JENKINS-21411 Shrinking and expanding range for diff view (job view only)
Using correct Date timestamps for timestamp test
Typo
IT fixed (headline changed)