Move <regex> inclusion to C4Include

Since multiple source files may want to use regular expressions, move
the header inclusion before setting up heap debugging.

src/C4Include.h

@@ -66,6 +66,14 @@ don't need to include this file or any of the files it includes. */
 #include <utility>
 #include <vector>
 
+#ifdef USE_BOOST_REGEX
+#	include <boost/regex.hpp>
+	namespace re = boost;
+#else
+#	include <regex>
+	namespace re = std;
+#endif
+
 // debug memory management - must come after standard and boost headers,
 // because those libraries use placement new
 #ifndef NODEBUGMEM

src/c4group/C4Language.cpp

@@ -31,15 +31,6 @@
 #include <C4Config.h>
 #include <C4Game.h>
 
-#ifdef USE_BOOST_REGEX
-#	undef new
-#	include <boost/regex.hpp>
-	namespace re = boost;
-#else
-#	include <regex>
-	namespace re = std;
-#endif
-
 #ifdef HAVE_ICONV
 #ifdef HAVE_LANGINFO_H
 #include <langinfo.h>