Merge pull request #13 from redding/jcr-symbolize-template-names

Symbolize template names with `render`
Add a `partial` helper method for rendering partials

This adds a `partial` helper method for rendering partials
using view handlers. This, just like the `render` method,
leverages Sinatra's template rendering. This allows rendering
templates within other templates.

This organizes the rendering functionality in to a `Template` and
`Partial` class. The `Partial` is a specialized kind of
`Template`. In particular, it expects the files to be named with
a leading underscore and only accepts `locals`, instead of any
Sinatra rendering options.

Closes #9
Merge pull request #14 from redding/jcr-partial-helper

Add a `partial` helper method for rendering partials
Add nested layouts support to Deas

This adds nested layout support to Deas. Through Sinatra, Deas
supported a single layout, but now it will use Sinatra's
interface for nested layouts. This can be done by passing a
`:layout` or `:layouts` option to the render method. These
are then rendered left-to-right, so the left-most layout is
the outermost layout. Additionally, Sinatra's block style for
nested layouts can be used with the `render` helper. This will
allow view handlers to render their templates in a variety of
ways and also support rendering them within many layouts.
Merge pull request #15 from redding/jcr-support-layouts

Add nested layouts support to Deas
Add escaping helpers to template's render scope

This adds escaping helpers to the template's render scope. This
allows escaping HTML or URLs when needed in a template. This is
to prevent XSS attacks. These methods use the common ruby
community naming conventions of `h` for html escaping and `u`
for url escaping.

Closes #4
Merge pull request #17 from redding/jcr-escaping

Add escaping helpers to template's render scope
Allow setting Sinatra's `show_exceptions` option

This exposes Sinatra's `show_exceptions` option through the
`Deas::Server`. This allows controlling when you get Sinatra's
error pages or just the generic ones.

Closes #11
Merge pull request #19 from redding/jcr-show-exceptions

Allow setting Sinatra's `show_exceptions` option
Add request logging to Deas

This adds request logging to Deas, both verbose and summary
logging. The type of logging can be toggled using the
`verbose_logging` option on the `Deas::Server`. This allows
developers to analyze how long a request takes and also see
more details about the request and response.