"Replace all" elision

[abhinav]

Currently, patches with elisions only replace the first instance of the matched contents.

For example,

 f(..., 
-  "GET",
+  constants.Get,
  ...,
 )

This will only replace the first instance in a matching function call.

// Input
foo(a, b, "GET", c, "GET", d)

// Expected
foo(a, b, constants.Get, c, constants.Get, d)

// Actual
foo(a, b, constants.Get, c, "GET", d)

gopatch should either treat ..., foo, ... transformations as "replace all", or we should add support for contextual transformations sooner (#11).