autocomplete funcs with parens, replace current identifier

[cpirich]

• Modify autocomplete so that we replace the entire identifier (previously, we only replaced the text before the cursor that was used as the filterText). Example: if you have a call to randomNumber(), then move the cursor to between the r and the a and type s, you will see a dropdown with matches for items that contain r before s (filterText is rs) - including readRecords, like this:

• If you select readRecords from the dropdown above, we now replace rsandomNumber with readRecords. Previously, we'd only replace rs with readRecords and you'd end up with readRecordsandomNumber
• Change autocomplete to append a pair of parentheses when completing a function name (but not a property). We also move the cursor back in between the parentheses if the function expects parameters, and the parameter autocomplete / tooltip will automatically kick in for the first param.
• We previously did something similar in starwars playlab under a flag called autocompleteFunctionsWithParens - but that mode also added a semicolon. That mode has been renamed to autcompleteFunctionsWithSemicolon and the behavior is preserved.
• Added special handling for the case where you are modifying a function call (as in the first example above), such that we don't add parentheses since they are already present, but we move the cursor forward into the position of the first parameter if the function has parameters.

Examples
autocompleting a function that expects a parameter:

autocompleting a member function that expects a parameter,
autocompleting a member property,
autocompleting a member function that does not expect a parameter,
autocompleting an existing member function call to a different function call (multiple times):

[islemaster]

Cool! Seems much better.