add ability to allow fractional allocation of precincts

[happyjack27]

add ability to allow fractional allocation of precincts. this would help with situations where the precinct to district ratio is low.

the contiguous rule is violated if:

• a district that's fractionally allocation has no neighbors that border that precinct
• a fractionally allocated district is surrounded by all fractionally allocated districts
• a fractionally allocated district is surrounded by more than 3 fractionally allocated districts

this needs to be fleshed out more.