Adds support for continuing to track tables across function calls

[arichard4]

On top of #65

The basic idea:
When a function is called, there's a few things relevant to table fields that could happen:
(1) The function could be called as a method, i.e. invoked on a table, i.e. table:function(); we need to stop tracking it
(2) The table as a whole could be passed to the function; we need to stop tracking it
(3) Externally accessible fields could have arbitrary reads, writes, or aliases; we need to stop tracking them
(4) A specific field from the table could be passed; this is an access to that field

Here's some sample code to illustrate why cases 1-3 need to outright stop tracking the table in question, rather than marking all keys are potentially read/written and marking the table as being externally referenceable:

local t
local function func1(var)
   t = var
end
local x = {}
func1(x)
x[1] = 1
print(t[1])

local z = {}
local a
function z:func() a = self end
z:func()
z[1] = 1
print(a[1])

local y
local function func2() return y end
function func3()
   y = {}
   local t = func2()
   y[1] = 1
   print(t[1])
end

Note that this is one of two pieces of function-call related functionality; the other is handling for builtin functions: type, pairs, ipairs, next, table.insert, table.remove, table.sort, table.concat.