Trying out (Si|Or)lex for the web UI

This is an experimental branch to test out usage of Silex with
Orlex as the framework backing the web frontend. Included in this
commit is a base setup of Silex with controller organization
handled by the Orlex project and setup for the Twig templating
engine.
Tweaks for Travis build

The Travis build was having issues because it was a) using an
outdated global install of composer and b) I had a requirement of
PHP v5.4.15 which is a problem on the Travis system or within
composer itself. I bumped the required version of PHP down to 5.4.0
to hopefully fix the build.
Integrating assetic and Twitter Bootstrap

Decided to use the Assetic project to handle asset management.
Integrated that using the Silex-Assetic project to concat all CSS
and JS resources into the public docroot. I also want to use LESS
for this project so I included LESS processing in the Assetic
setup.

Additionally I moved the docroot for the webserver from a synced
directory to the /vagrant directory which is synced by default.
Updating versions in composer.json
Taking advantage of new Orlex cache
Refactoring config to use environment

Previously was using a complicated system of environment-based
configuration files, i.e., dev.php, prod.php, etc. This commit
adds an environment variable to specify an environment and then
configures certain directives, such as debug mode, accordingly.
Merge branch 'master' into silex-integrate

Conflicts:
	composer.lock
Updating dependencies after merge of master.
Merge pull request #2 from jcarouth/silex-integrate

Integrate Silex for the web frontend