Cases currently not handled (^ marks the caret):

• [obj method:NSArray arrayWithObject:foo, bar, nil^]
• anything involving expressions probably doesn't work
• 0 and friends are incorrectly recognized as receivers in some circumstances

We also need to:

• make it only search inside the brackets/paren set the caret is in
• probably make it skip over ] in situations like: [obj method^]
• when multiple insertion places are possible, look at the selectors which would arise from each candidate, and pick the one we have in our index (index being a hash of all the Cocoa/WebKit selectors)

Done:

• obj doMethodWithString:@" "^
• anything involving strings should work decently