Changed syntax of translation handlebars statements

Namespaces will now be defined with the {{#namespace}}{{/namespace}
block expression. Each namespace must have the attribute "name". If
none namespace is defined, the inner translations belong to the global
space.

The expression for defining a translation changed as well. A
translation is now defined by the {{translation}} block expression. It
must contain the attribute "key". Optionally you can overwrite the
inherited namespace by defining the attribute "namespace".

Furthermore, changed some filenames and moved the dependency from the
TranslationModel out of TranslateMe into the translation parser.