Adds support for building a `.deb` package for Debian or Ubuntu using "Official" tools(debuild, etc)

This creates a Debian package which configures an I2P browser as an application in /usr/bin/i2pbrowser and which adds .desktop files to create shortcuts to I2P browsing functionality in the start menu's of standard desktop environments. It will work any Debian-based distro with a modern sh and should build on Launchpad. Closes #5 (closed)