Make Event::lastest_in_projects side-effect free if passed an empty array of project_ids
Make Event::lastest_in_projects side-effect free if passed an empty array of project_ids

spencerwp/mainline,grjones/gitorious-submodule-dependencies,Gitorious-backup/mainline,Gitorious-backup/yousource,gitorious/mainline,elcom/gitorious,tigefa4u/gitorious-mainline,crazycode/gitorious,rae/gitorious-mainline,deld/gitorious,Gitorious-backup/mainline,cynipe/gitorious,Gitorious-backup/yousource,cynipe/gitorious,balcom/gitorious,ericbutters/eric-gitorious,njall/wel-gitorious,vymiheev/Gitorious-OpenStack,Gitorious-backup/vsr-mainline,tigefa4u/gitorious-mainline,Gitorious-backup/yousource,Gitorious-backup/vsr-mainline,adg29/asi.gitorious,elcom/gitorious,deld/gitorious,SamuelMoraesF/Gitorious,adg29/asi.gitorious,gitorious/mainline,njall/wel-gitorious,Gitorious-backup/yousource-features,victori/gitorious-jruby,SamuelMoraesF/Gitorious,grjones/gitorious-submodule-dependencies,gnufied/gitorious,adg29/asi.gitorious,ericbutters/eric-gitorious,rae/gitorious-mainline,spencerwp/mainline,tigefa4u/gitorious-mainline,elcom/gitorious,water/mainline,water/mainline,Gitorious-backup/franklin-devs-phpbbhub,Gitorious-backup/vsr-mainline,tigefa4u/gitorious-mainline,crazycode/gitorious,SamuelMoraesF/Gitorious,altrair/gitorious-openstack,crazycode/gitorious,victori/gitorious-jruby,gnufied/gitorious,feniix/gitorious,grjones/gitorious-submodule-dependencies,vymiheev/Gitorious-OpenStack,Gitorious-backup/yousource-features,gitorious/mainline,water/mainline,rae/gitorious-mainline,cynipe/gitorious,spencerwp/mainline,ericbutters/eric-gitorious,Gitorious-backup/franklin-devs-phpbbhub,Gitorious-backup/mainline,gitorious/mainline,Gitorious-backup/franklin-devs-phpbbhub,victori/gitorious-jruby,altrair/gitorious-openstack,Gitorious-backup/franklin-devs-phpbbhub,rae/gitorious-mainline,njall/wel-gitorious,Gitorious-backup/yousource,SamuelMoraesF/Gitorious,Gitorious-backup/yousource-features,feniix/gitorious,balcom/gitorious,Gitorious-backup/vsr-mainline,Gitorious-backup/mainline,elcom/gitorious,adg29/asi.gitorious,balcom/gitorious,spencerwp/mainline,feniix/gitorious,altrair/gitorious-openstack,gnufied/gitorious,Gitorious-backup/yousource-features,vymiheev/Gitorious-OpenStack,deld/gitorious