Add support for configuration files written in Lua

This patch adds support for configuration files written in Lua, arguably a better way to represent configuration.

Example
------------

.moos Syntax:
```
ServerHost = localhost
ServerPort = 9000 
// this is a comment 
ProcessConfig = pLuaCfg
{ 
    aString = MyStringValueNoSpaces
    aSpacedString = S P A C E S 

    aDouble = 3.141 

    aBoolTrue = true 
    aBoolNotTrue = false 

    aMultiString = a 
    aMultiString = b 
    aMultiString = and so on 

    aNullVal = 
}
```

Lua Syntax (same data)
```lua
ServerHost = "localhost"
ServerPort = 9000 
-- this is a comment 
pLuaCfg = { 
    aString = "MyStringValueNoSpaces", 
    aSpacedString = ("S P A C E S"):gsub(" ", ""), 

    aDouble = 3.141, 

    aBoolTrue = true, 
    aBoolNotTrue = false, 

    aMultiString = { 
                    "a", 
                    "b", 
                    ("and so on"):gsub(" ", ""), }, 

    aNullVal = nil, 
}
```

Backwards Compatibility
------------------------------------
Configuration files will be loaded into a Lua environment.  If that fails (i.e., if they do not parse), then the file will be parsed as a normal .moos file.

Extras
---------
This code supples MOOSLuaEnvironment, which allows other uses of Lua files in MOOS.  For example, as a Lua scripted MOOS App.

Slides here: http://oceanai.mit.edu/moos-dawg11/material/23-brief-katz.pdf