Better mod support

[Bilka2]

The big boy.

Dependency parsing issues

• Doesn't deal with spaces in mod names. - Fixed in #44
• Doesn't deal with no space between symbol (e.g. ?) and mod name. - Fixed in #44
• Doesn't deal with ~ and ! (presumably (?) is also broken, but less important to get fixed). - Fixed in #44
• Doesn't default to requiring base when no dependencies given (may be the cause of #26). - Fixed in cf8aa7a

Require() issues

• Jetpack 0.2.13 requires with ".lua" in the string, results in looking for prototypes/phase1/jetpack\\lua.lua, but the java side loader.lua require works - find out what is going on. - Fixed in bc7321d
• package.loaded is kept between mods, breaks requiring when two mods have file with same name and require without full path. - Fixed in #46
• package.loaded is kept between settings and data stage. - Fixed in #46
• Add package alias for core/base/mods in general (#20)
• Requires relative to the current folder do not work in unzipped mods (do work in zipped mods)

Enhancements

• Load mod setting values from mod setting file (after loading setting prototypes) - requires parser for binary file type
• Make sure the mod ordering via dependencies works correctly
• Report incompatibilities and missing mods even when dependency doesn't affect load order (~ and ! support)

Optional

• Use Factorio's serpent
• Use Factorio's Lua - can Java interact with the C API?