Merge branch 'pw/maint-p4-rcs-expansion-newline'

I do not have p4 to play with, but looks obviously correct to me.

* pw/maint-p4-rcs-expansion-newline:
  git p4: RCS expansion should not span newlines

git-p4.py

@@ -227,7 +227,7 @@ def p4_keywords_regexp_for_type(base, type_mods):
         pattern = r"""
             \$              # Starts with a dollar, followed by...
             (%s)            # one of the keywords, followed by...
-            (:[^$]+)?       # possibly an old expansion, followed by...
+            (:[^$\n]+)?     # possibly an old expansion, followed by...
             \$              # another dollar
             """ % kwords
         return pattern