Improvements for REPL-driven development

This commit does the following:

* Adds a gitignore for `dev/user.clj` so that developers can create
  a file there w/o worrying about it getting tracked in VCS
* Modifies `dev/user-repl.clj` so that developers can override the
  default REPL Puppet Server config settings in their own `user`
  namespace.
* Provides an example `user.clj.sample` file, which can be copied
  to `user.clj`, which has an example of how to override the
  config settings plus a convenience function for loading the
  `user-repl` namespace and launching Puppet Server.
* Modify `project.clj` to define `user` as the default REPL
  namespace.
(SERVER-136) Add docs for http client SSL config
(SERVER-136) add link to oracle docs for cipher suites
Merge pull request #256 from cprice404/maint/master/SERVER-136-docs-for-http-client-ssl-config

(SERVER-136) Add docs for http client SSL config
Merge pull request #257 from cprice404/maint/master/repl-improvements

Improvements for REPL-driven development
(SERVER-112) Clean up puppet server ruby config

Prior to this commit, we were passing in the optional profiler
object from the Clojure code to the Ruby code as a first-class
argument to the constructor of our Ruby `Master` class.

It's becoming clear that we're going to have more of these
Puppet-Server-specific config options that we have to pass through
over time (including some things that will be coming soon in order
to complete SERVER-112), so this commit refactors the code to
pass in a map containing *all* Puppet Server settings as a single
argument.

It also makes an initial effort to start moving the handling of
some of those settings into the Puppet::Server::Config class,
and tries to group them together a bit more inside the body
of the `Master` constructor.
(SERVER-112) Refactor ruby settings initialization

This commit just introduces some new methods to help take care
of Ruby settings initialization, in preparation for cleaning
up `master.rb` a bit.
(SERVER-112) Move puppet/puppetserver ruby config out of `master.rb`

`master.rb` was getting pretty hairy.  This commit moves the code
related to initializing Puppet Server's ruby stuff into the
Puppet::Server::Config class, and introduces a new class
Puppet::Server::PuppetConfig to house the Puppet ruby initialization.
(SERVER-112) Move `execution` code into its own class

The `Execution` stuff seemed out of place in `master.rb` and
`config.rb`, so this moves it to its own spot.
(SERVER-112) Move request handler logic to module

There was a lot of logic related to the Puppet::Network::HTTP::Handler
module that was inlined in `master.rb`.  This commit simply moves
it into its own module that we can mix in instead of mixing in
the one from Puppet directly.
(SERVER-112) Move `run_mode` to end of file

The `run_mode` method in `master.rb` was defined in the middle
of the methods that satisfy the `JRubyPuppet` Java interface.
This commit simply moves the method down so that all of the
methods related to that interface are grouped together.
(SERVER-112) Missing 'require', prioritize logging init