added a note about function overloading via mbstring (closes #100, closes #55)
added a note about function overloading via mbstring (closes #100, closes #55)

handautsav/swiftmailer,voku/swiftmailer,zghosts/swiftmailer,peterkokot/swiftmailer,jamesggordon/swiftmailer,tweakers-dev/swiftmailer,fvosberg/swiftmailer,tweakers-dev/swiftmailer,Pardot/swiftmailer,papagel/swiftmailer,zghosts/swiftmailer,michabbb-backup/swiftmailer,denpamusic/swiftmailer,papagel/swiftmailer,peterkokot/swiftmailer,UofSC/php-shared-functions,gencer/swiftmailer,c960657/swiftmailer,UofSC/php-shared-functions,gburyakovsky/swiftmailer,michabbb-backup/swiftmailer,deguif/swiftmailer,gburyakovsky/swiftmailer,robertklein/swiftmailer,Dubz/swiftmailer,Pardot/swiftmailer,swiftmailer/swiftmailer,kuslahne/swiftmailer,handautsav/swiftmailer,UofSC/php-shared-functions,swiftmailer/swiftmailer,robertklein/swiftmailer,Chhunlong/swiftmailer,Chhunlong/swiftmailer,c960657/swiftmailer,Rotzbua/swiftmailer,gencer/swiftmailer,jamesggordon/swiftmailer,Pardot/swiftmailer,voku/swiftmailer,peterkokot/swiftmailer,kuslahne/swiftmailer,Rotzbua/swiftmailer,Dubz/swiftmailer,Pardot/swiftmailer,deguif/swiftmailer,fvosberg/swiftmailer,denpamusic/swiftmailer