Allow multiple government types to be added to a Faction

Lua Faction:govtype now adds the govtype to the Faction's govtypes list
rather than changing the faction's sole govtype.
Custom systems are now included in the first faction that has the
system's govtype in its list (essentially no change)
Standard systems take the first govtype of the faction they are a member
(used to take the Faction's sole govtype, taking the first was the
simplest for me to implement).
Federation Faction definition now includes 'Earth Colonial Government'
as well as 'Earth Democracy'. This should bring Barnard's star back into
the Federation fold.

Conflicts:
	src/Factions.cpp
Clean-up of Faction usage in Polit

Crime and legality methods now use StarSystem->GetFactionIdx() rather
than looking it up index via a link from govType retrieved from
StarSystem->GetSysPolit()
Removed Faction index from politDesc_t
Moved SysPolit::GetAllegianceDesc to StarSystem::GetAllegianceDesc
Pick System's govType randomly from Faction's govType list

No longer always picks first (last?) in the list.
New Faction::RollGovType method taking an MTRand makes the selection
(May need renaming?)
Removed code for setting get CustomSystem's based on its govType.
Added factionIdx member to CustomSystem in preparation for enabling
setting of CustomSystems Factions from Lua.

Conflicts:
	src/Factions.cpp
Handle Factions with no GovTypes better

Now picks at random from the list of all government types.
Allow Lua to set Faction of Custom Systems

Example system in data\systems\custom\05_rondel.lua
Faction::GetIndexOfFaction method could probably be done better by
someone more familar with C++
Distribute appropriate GovTypes among existing factions

Independent gets everything non-specific.
Federation gets EARTH* (except EARTHMILDICT maps to 'Military
Dictatorship' but doesn't say anything about Earth)
CIS gets CIS*
Red gets EMPIRE*
Add weighting to selection of govTypes, when picked from Faction

Lua Faction:govtype renamed to Faction:govtype_weight and now takes a
second argument for the weight.
Current Faction definitions updated to the new format.
Faction::RollGovType renamed Faction::PickGovType.
Faction::PickGovType now weights its selection.
Tighten implementation of govtype weighting

govTypes renamed to govtype_weights.
govtypes_weights switched to std:vector<pair> rather than std:map
added Lua warning for weight < 0
Tweaks for Faction List now being std::vector<Faction*>
Merge branch 'feature/faction-multigov' into feature/factions-auto
Add autogenerated factions

Mostly done through /data/factions/99_AutoGeneratelua, but also
needed some changes on the Factions C++ side so allow Lua to
roll up a Faction without knowing whether a proposed home sector
actually has any systems in it.
Add missing return to skip case of Faction::l_fac_add_to_factions
Rewrite Faction::GetIndexOfFaction to use a Map

I may just be pushing spaghetti about on the plate here, but this
adds a map from faction name to faction index, and switches the
code in Faction::GetIndexOfFaction from the unpleasant brute force
scan to using the map instead.
Define weighting of government types for auto-factions

Added a list of government types with least stable at either end.
The government types for each faction should peak around a particular
point in that list, with varying spread, and flatness of the curve
around it.
Define illegal goods probabilities for auto-factions

Now generates illegal goods probability lists for the factions.
Chucked in Robots as a possible illegal good.
Add Liquor back in as a possible choice as an illegal good

...for all those dry factions out there :)
Add naive adjustment to make generated colours less muddy

Attempts to bump up the luminance if it's looking in a way that
will induce hair-pulling among anyone who (unlike me) actually
knows what luminance is.
Add auto-generation of Police and Military names

...not that they're currently visible anywhere (I don't think?)
Added some air-force-y sounding military options

Added Space Arm, Defense Wing, and Battle Flight.
Also tweaked Guard->Guards, Patrol->Space Patrol & Warfleet->War Fleet.
Merge branch 'feature/faction-multigov' into feature/factions-auto