Support gpg4win registry keys and install location
* src/client.cc (default_uiserver_cmdline): Rewrite based on GpgOL. * src/main.cc (get_debug_file): Use new keys. * src/registry.h (REGKEY): Replace by GPG4WIN_REGKEY_2/3 add x64 key.
This tries harder to find kleopatra or GPA and looks in both the old
GNU GnuPG registry key as in the new Gpg4win registry key. Also
it looks both under /bin and not in /bin subfolder.