environment pointer as parameter and return pointer to corresponding
win32 environment block if != NULL. Otherwise just sync as before.
(cygwin_internal): Add CW_CVT_ENV_TO_WINENV case.
* include/cygwin/version.h: Bump API minor number.
* include/sys/cygwin.h (cygwin_getinfo_types): Add CW_CVT_ENV_TO_WINENV.