* shared_info.h (open_shared): Create function wrapper for common use case.

* shared_info.h (open_shared): Create function wrapper for common use case.
(open_shared): Change fifth argument to a pointer rather than a reference.
* fhandler_console.cc (fhandler_console::get_tty_stuff): Eliminate use of dummy
variable and call open_shared with constant.
* fhandler_process.cc (format_process_mounts): Ditto.
* pinfo.cc (pinfo::init): Pass pointer to shloc.
* shared.cc (shared_mem_inited): New variable.
(open_shared): Crate function wrapper for common use case.
(open_shared): Accommodate change to fifth argument to a pointer.
(shared_info::initialize): Remove spinlock test.  Simplify function.  Move
get_session_parent_dir call back here.
(memory_init): Protect global shared settings with shared_mem_inited spinlock.
Move get_session_parent_dir call to shared_info::initialize.