Detect exec bit in more cases.

git-p4 was missing the execute bit setting if the file had other attribute
bits set.

Acked-By: Simon Hausmann <simon@lst.de>
diff --git a/contrib/fast-import/git-p4 b/contrib/fast-import/git-p4
index 55778c5..65c57ac 100755
--- a/contrib/fast-import/git-p4
+++ b/contrib/fast-import/git-p4
@@ -63,6 +63,14 @@
     if os.system(cmd) != 0:
         die("command failed: %s" % cmd)
 
+def isP4Exec(kind):
+    """Determine if a Perforce 'kind' should have execute permission
+
+    'p4 help filetypes' gives a list of the types.  If it starts with 'x',
+    or x follows one of a few letters.  Otherwise, if there is an 'x' after
+    a plus sign, it is also executable"""
+    return (re.search(r"(^[cku]?x)|\+.*x", kind) != None)
+
 def p4CmdList(cmd, stdin=None, stdin_mode='w+b'):
     cmd = "p4 -G %s" % cmd
     if verbose:
@@ -916,7 +924,7 @@
                 data = file['data']
 
                 mode = "644"
-                if file["type"].startswith("x"):
+                if isP4Exec(file["type"]):
                     mode = "755"
                 elif file["type"] == "symlink":
                     mode = "120000"