Expand braces internally, as POSIX /bin/sh does not do {} expansion.

Signed-off-by: Russell Steicke <russells@adelie.cx>

src/Transport.h

@@ -43,6 +43,9 @@ public:
   virtual void send (const std::string&) = 0;
   virtual void recv (std::string) = 0;
 
+  void expand_braces(const std::string& path, const std::string& sourceortarget,
+                     std::vector<std::string>& paths);
+
   static bool is_directory(const std::string&);
   static bool is_filelist(const std::string&);