Refactor dotfiles to do less by default

[danemacmillan]

At the moment, dotfiles will install tonnes of things in addition to its files. This has become a problem on production servers that should be as barebones as possible. Often, the dotfiles dependencies will install far more than is needed.

What should it do now?

Dotfiles should only install the bare minimum required utilities that are needed in order for the dotfiles to be useful. Anything beyond that, like installing a language interpreter, compilers, etc, are superfluous. In other words, if not a single dotfile requires that one of those installs are required to function, it should not install by default.

What needs to be changed?

The dpm utility should have categories of installations. By default, without options provided to it, it will install the necessarty utilities for the dotfiles to function. If the machine requires more, pass a flag, like --development, and it will install all the additional developer tools, or --localmachine, and it will install all the extra tools like weechat.

[danemacmillan]

Part of this was done in #24 and #25. Numerous packages were commented out by default.

Eventually some can come back, but the goal should be to include only the minimal number of packages for the dotfiles to work, and for there to be a sufficient baseline to then begin development work that will involve additional packages relevant to the given codebase.