[SYSTEMINFO] Do some code lift-up; use Conutils lib to be able to display localized unicode strings

In particular:
- unhardcode buffer sizes and API flags;
- add our standard file header in the .c file (I haven't done it for
  the other files);
- merge systeminfo.rc and rsrc.rc together.

Author: HBelusca

modules/rosapps/applications/sysutils/systeminfo/CMakeLists.txt

@@ -1,9 +1,10 @@
 
 include_directories(
+    ${REACTOS_SOURCE_DIR}/sdk/lib/conutils
     ${REACTOS_SOURCE_DIR}/sdk/lib/udmihelp)
 
 add_executable(systeminfo systeminfo.c systeminfo.rc)
-set_module_type(systeminfo win32cui)
-target_link_libraries(systeminfo udmihelp)
+set_module_type(systeminfo win32cui UNICODE)
+target_link_libraries(systeminfo conutils udmihelp ${PSEH_LIB})
 add_importlibs(systeminfo user32 advapi32 netapi32 shlwapi iphlpapi ws2_32 msvcrt kernel32 ntdll)
 add_cd_file(TARGET systeminfo DESTINATION reactos/system32 FOR all)