[core] handle search improvements

* Fix memory leaks due to not releasing the heap
* Also speed up lookups by not reopening the same process twice in a row
* Also make the usb_debug variable global so we can use uuprintf everywhere

src/stdfn.c

@@ -32,7 +32,6 @@
 
 #include "settings.h"
 
-extern BOOL usb_debug;	// For uuprintf
 int  nWindowsVersion = WINDOWS_UNDEFINED;
 int  nWindowsBuildNumber = -1;
 char WindowsVersionStr[128] = "Windows ";