Add support for karma-aliasing

[dsprenkels]

Add support grouping terms together by using aliases.

Example:

<+Daan> }karma c++
<DaZeus> c++ has a karma of 13 (+19, -6)
<+Daan> }karma cpp
<DaZeus> cpp has a karma of 2 (+2, -0)
<+Daan> }karma-alias merge c++ cpp
<DaZeus> gouped together c++ and cpp
<+Daan> }karma c++
<DaZeus> c++ has a karma of 13 (+21, -6)
<+Daan> }karma-alias split c++
<DaZeus> ungrouped c++ and cpp

[dsprenkels]

Cc @AaronVanGeffen

[Minnozz]

Maybe make them top level commands?

}karma-merge c++ cpp
}karma-split c++

I think those are easier to remember.

[Minnozz]

Another suggestion:

<+Daan> }karma c++
<DaZeus> c++, cpp have a grouped karma of 13 (+21, -6)

[AaronVanGeffen]

We probably also want to support denoting identifiers with quotes, like factoids:

<+Daan> }karma-merge "de speld" speld
<+Daan> }karma-split speld "de speld"