Add an option to enable ldb

Check out http://github.com/laarmen/lua_debug to get the software
Patches welcome!
Add an @prefix to the chunk sources to more or less match the original Lua nomenclature
#1734  UI: speeding up the buy and sell process in the marketplace
Avoid virtual setters during Load/initialisation. Fixes #2221.

Load/Init should only be setting up state, whereas virtual setters are
often overriden in derived classes to trigger things on particular state
changes (e.g., put a message in the ship console when the ship alert state
changes). Load/Init is not a state change, because there's no (valid)
previous state.
Merge pull request #2223 from johnbartholomew/issue-2221

Avoid virtual setters during Load/initialisation
set ship type through SetShipId to include property update

fixes #2225
Merge remote-tracking branch 'johnbartholomew/issue-2225'
Create one StaticGeometry node per aiMesh, and reuse them when possible
update changelog: add a couple of missing issue refs
Merge remote-tracking branch 'laarmen/lua_debug'
Merge pull request #2188 from UncleVasya/buy_sell_speedup

#1734  UI: speeding up the buy and sell process in the marketplace
update changelog
StarSystem:ExportToLua() does not return anything
add FileSystem::SanitiseFileName
be safer about the generated file-name in ExportToLua
Add new ellipsoid terrain height class.

This class creates an ellipsoid surface representing equatorial bulges
for rotating bodies by returning the height value between a point on a
sphere of Polar radius and a point on the ellipsoid surface in the
center to Polar radius line (using the aspect ratio which gives
Equatorial to Polar radius).
allow CustomBody to control SystemBody aspect ratio
Show radius and equatorial bulge ratio for stars in system-info-view

New translatable string EQUATORIAL_RADIUS_TO_POLAR_RADIUS_RATIO.
Enable ellipsoid surfaces for all stars.
Create aspect ratio between 1.0 and 1.8 for stars of type O, A, B, F in sysgen.