Additional configuration enhancements (TODO import)

- config for long int sysconf (int parameter) Function This function is used to inquire about runtime system parameters. The parameter argument should be one of the _SC_ symbols listed below. The normal return value from sysconf is the value you requested. A value of -1 is returned both if the implementation does not impose a limit, and in case of an error. The following errno error conditions are defined for this function:
`EINVAL The value of the parameter is invalid.` enums: _SC_PAGESIZE Inquire about the virtual memory page size of the get page size returns the same value (see Query Memory Parameters). _SC_PHYS_PAGES Inquire about the number of physical pages in the system. _SC_AVPHYS_PAGES Inquire about the number of available physical pages in the system.

- config for The ulimit Function: The ulimit function can be used to get and set certain process limits. #include long ulimit (int cmd, /* long newlimit */...); Returns: the value of the requested limit if OK, -1 on error The ulimit function allows a process to get or set some of its limits. The operation performed is determined by the value of the cmd argument, which must be one of the following four values: UL_GMEMLIM This returns the maximum amount of memory the process may use. On successful completion, the requested limit is returned. Otherwise, -1 is returned and the limit is not changed.