Add semicolon (';') as a sentence delimiter

[lafrenierejm]

Include ';' in the first regular expression grouping in l:re_term.

[reedes]

Thanks for the pull request.

This is different behavior from the default sentence object.

Let me think about this. It might be better as a configurable option.

[lafrenierejm]

It might also be worth pointing out that the method of handling semicolons proposed by the PR does not correctly follow the grammatic definition of a sentence: it is incapable of recognizing the use of semicolons to delimit items in a list.

[alerque]

I agree this is useful in some circumstances but do not thing it should be the default. This should be arranged somehow similar to #17 so that it is a user configurable option. Perhaps after that is merged this could just document how to add ; as a terminator using that feature.