Configuration improvements

Add a 'slim' section to config.php.dist so that we can configure
the mode and other configuration more easily. Ensure that the
view is instantiated in index.php though.

Also, only set error_reporting and display_errors when the mode is
set to development.

Note that we load config.php.dist if a config.php is not set. This
mean that it is assumed that the live site has its own config.php.
Merge pull request #22 from akrabat/config

Configuration improvements
Removed the instructions for the vagrant vm. The vm is in it's on repo
now.
Merge pull request #23 from EricHogue/JOINDIN-314-RemoveVMDocumentation

Changed the vagrant instructions to use the new vm JOINDIN-314
Merge branch 'master' of github.com:joindin/responsive