RFR 8210318: idea.sh script doesn't work on Mac

[Maurizio Cimadamore]

Hi,
following the latest updates to the idea.sh script, Mac users reported 
issues - mostly having to do with usage of 'sed' - more specifically:

* sed -i option is not portable - it has different formats in Mac vs. 
Linux. This patch does without -i, by moving the replaced file onto a 
temporary file, then moving such file on top of the template file in a 
subsequent step. This should be more robust.

* sed doesn't like newlines in replaced text in Mac. I've thus omitted 
the newline from the SOURCE template - as that was mostly cosmetic.

Thanks for Michael McMahon to report (and figure out how to deal with) 
these issues, and to Alan Bateman for testing the patch.

I also fixed another minor glitch, this time in the langtools-only 
template - which was still referring to the old ant file location in the 
various run configuration.

Webrev:

http://cr.openjdk.java.net/~mcimadamore/8210318/

Cheers
Maurizio