nmap: help zenmap to find it's templates in nix-store

Zenamp wrapper confuses python so it thinks that zenmap is launched as a script
and not as an executable. This leads to incorrect /share path and missing
templates. ./zenmap.patch cures that (a bit hacky as usual).

pkgs/tools/security/nmap/zenmap.patch

@@ -0,0 +1,15 @@
+diff -ruN nmap-5.50.orig/zenmap/zenmapCore/Paths.py nmap-5.50/zenmap/zenmapCore/Paths.py
+--- nmap-5.50.orig/zenmap/zenmapCore/Paths.py	2013-06-06 05:52:10.723087428 +0000
++++ nmap-5.50/zenmap/zenmapCore/Paths.py	2013-06-06 07:07:25.481261761 +0000
+@@ -115,7 +115,10 @@
+     else:
+         # Normal script execution. Look in the current directory to allow
+         # running from the distribution.
+-        return os.path.abspath(os.path.dirname(fs_dec(sys.argv[0])))
++        #
++        # Grrwlf: No,no,dear. That's not a script, thats Nixos wrapper. Go add
++        # those '..' to substract /bin part.
++        return os.path.abspath(os.path.join(os.path.dirname(fs_dec(sys.argv[0])), ".."))
+
+ prefix = get_prefix()
+