civicrm: v5.1.0 release

.github/CONTRIBUTING.md

.github/PULL_REQUEST_TEMPLATE.md

civicrm.php

civicrm/CONTRIBUTORS.txt

civicrm/CRM/Activity/Form/Activity.php

civicrm/CRM/Activity/Form/ActivityView.php

civicrm/CRM/Admin/Form/ScheduleReminders.php

civicrm/CRM/Campaign/Form/Task/Interview.php

civicrm/CRM/Contact/BAO/Contact/Permission.php

civicrm/CRM/Contact/Form/Edit/Address.php

civicrm/CRM/Contact/Form/Merge.php

civicrm/CRM/Contact/Form/Search.php

civicrm/CRM/Contact/Form/Search/Criteria.php

civicrm/CRM/Contact/Import/Parser/Contact.php

civicrm/CRM/Contact/Page/DedupeFind.php

civicrm/CRM/Contribute/BAO/ContributionRecur.php

civicrm/CRM/Contribute/Form/Contribution.php

civicrm/CRM/Contribute/Form/Contribution/Confirm.php

civicrm/CRM/Contribute/Form/ContributionView.php

civicrm/CRM/Contribute/Form/Search.php