Merge pull request #5750 from onlyjob/spell

multiple spelling corrections

diff --cc CRM/Contribute/BAO/Contribution.php
Simple merge

diff --cc CRM/Core/BAO/CustomField.php
Simple merge

diff --cc CRM/Core/BAO/FinancialTrxn.php
Simple merge

diff --cc CRM/Core/OptionGroup.php
Simple merge

diff --cc CRM/Member/BAO/Membership.php
Simple merge

diff --cc CRM/Member/Form/Membership.php
Simple merge

diff --cc tests/phpunit/CiviTest/CiviUnitTestCase.php
Simple merge