Fixed check-express linkage for MSVC.

* Added SCL_EXPRESS_EXPORT flag for yydebug,yydbg_upper_limit,yydbg_lower_limit and yydbg_verbose
* Added xgetopt.cc for check-express/MSVC.
* Added inithook for check-express/MSVC?
* Used set_target_properties COMPILE_DEFINITIONS in stead of add_definitions
  for SCL_EXPRESS_EXPORTS/SCL_EXPRESS_IMPORTS.