RFR: JDK-8024200 : (xxs) hgforest.sh fails to detect Python correctly if space after shebang

[Mike Duigou]

Hello all;

This is a very small change to trim optional whitespace off of the interpreter directive which may appear in the hg wrapper script. The whitespace is legal per https://en.wikipedia.org/wiki/Shebang_%28Unix%29 and is now included in some distributions of mercurial (Ubuntu 13.04).

http://cr.openjdk.java.net/~mduigou/JDK-8024200/0/webrev/

Mike