bugfix for shifting replace values


![midification_shifting_bug](https://cloud.githubusercontent.com/assets/1905204/3945549/a5b6a974-2647-11e4-9192-8be80c2c06fe.jpg)
If using a normal 'search' and 'replace' several times:
E.g. searching for 
``date_format_short``

and replace it with
``datetime_format``

and the search term is existing several times in the file (I want to replace all occurences), the first replacement is correct, but every following match is shifting to the right (the value of $i).