Install 'fuse' instead of 'fuse-utils'

The 'fuse-utils' package doesn't exist on Ubuntu 14.04 and is marked as a
transitional package on both Debian 7 and Ubuntu 12.04 that installs the
'fuse' package.

Since Debian 7 is the officially supported distribution we can safely
switch to install 'fuse' instead of 'fuse-utils' and we also gain
compatibility with Ubuntu 14.04.
Add support for Apache 2.4 on Ubuntu 14.04
Add Ruby modeline to Vagrantfile

Editor which support Emacs modelines (e.g. SublimeText with a plugin
and Emacs itself) automatically enable Ruby syntax highlighting when
visiting the Vagrant configuration file.
Use box-cutter/debian75 for both VirtualBox and VMware

Use a single Vagrant base box since the one made by Box-Cutter supports both
VirtualBox and VMware (Workstation and Fusion) hypervisors.
Use proper configuration directives to tune VM memory
Vagrantfile: Add entries to test/develop against Ubuntu 12.04 and 14.04