Adding .gitignore based on the svn-ignores.

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@2839 e93f8b46-1217-0410-a6f0-8f06a7374b81

.gitignore

+/config/database.yml
+/config/email.yml
+/config/initializers/session_store.rb
+/coverage
+/db/*.db
+/db/*.sqlite3
+/db/schema.rb
+/files/*
+/log/*.log*
+/log/mongrel_debug
+/public/dispatch.*
+/public/plugin_assets
+/tmp/*
+/tmp/cache/*
+/tmp/sessions/*
+/tmp/sockets/*
+/tmp/test/*
+/vendor/rails