Add support for configurable template delimiters

This adds a new configuration variable for app.conf which allows for the template delimiters to be set as desired.  The new delimiters only affect files in the current project, thus built in templates and module templates are not affected.  Both delimiters are denoted in the same variable, and are separated by a space.  For example, adding the following to app.conf:

    template.delimiters = {% %}

Will set the left and right delimiters respectively.