refactoring:

- added CEXEBuild::update_exehead() and made everyone use it
 - renamed some variables (of the *exeheader* variety)
bug fix:
 - uninstaller CRC-check failed if !packhdr created a non-512-bytes-aligned exehead


git-svn-id: https://svn.code.sf.net/p/nsis/code/NSIS/trunk@3695 212acab6-be3b-0410-9dea-997c60f758d6

Source/util.h

@@ -79,4 +79,9 @@ int my_glob(const char *pattern, int flags,
 #define OPEN(a, b) open(a, b)
 #endif
 
+template <class T>
+inline T align_to_512(const T x) {
+  return (x+511) & ~511;
+}
+
 #endif //_UTIL_H_