Refactor sym_upload in tools to extract code into common/linux, and minor fixes

src/common/linux/http_upload.h

Index: src/common/linux/http_upload.h
diff --git a/src/common/linux/http_upload.h b/src/common/linux/http_upload.h
index 4f0e452f469d99dd2c9abde4745509a650b23fd5..bc1d5d5700b657669f47484420ddeece14cec950 100644
--- a/src/common/linux/http_upload.h
+++ b/src/common/linux/http_upload.h
@@ -74,6 +74,9 @@ class HTTPUpload {
   // any quote (") characters.  Returns true if so.
   static bool CheckParameters(const map<string, string> &parameters);
 
+  // Checks the curl_lib parameter points to a valid curl lib.
+  static bool CheckCurlLib(void* curl_lib);
+
   // No instances of this class should be created.
   // Disallow all constructors, destructors, and operator=.
   HTTPUpload();