Add API documentation.
Add API documentation.

ssinucodt/test,sebastianbergmann/money,HSarode-Compumatrice/money,Rimehch/php-exp,boekkooi/money,staabm/money,stefen/money,tungus28/money,junsanity06/Money,terryhuangbo/ut,cenxun/money,royopa/money,juicexiems/money,cerberosnash/jenkins,ankahla/jenkins-phpunit-example,cerberosnash/jenkins,balsing/Money,arleincho/money,ankahla/jenkins-phpunit-example,ojengwa/money,cerberosnash/jenkins