Use sudo's method (and code) to close file descriptors instead of iterating over every possible file descritor. In issue 5391 we see that closing file descriptors can take a very long time: 4 seconds in this user's case. We now close file descriptors in the file descriptor server before fork(). Since the file descriptor server is single-threaded, this works and is safe. Sudo uses opendir() after fork() which could deadlock, which we don't want to risk (and is a more serious concern for us since we're multithreaded) so when session restoration is disabled we still close every file descriptor because that's the state of the art on macOS (sigh).

When creating a new tab using the default profile when the current tab is a tmux tab, refer to the gateway session's current directory for the purposes of recycling the working directory. Issue 5320

Rate limit TIOCSWINSZ to 5/second to avoid signal coalescing preventing the remote from redrawing when size changes twice in rapid succession, as when you close a split pane with a per-pane title bar (1st the title bar goes away, causing a size change, and then the split goes away causing a second size change in rapdi succession). Issue 5096

Fix a bug where iTerm2 would hang when a fd server exited before we attached to it (which could happen if the command failed to exec or exited right away). Also fix a leak of file descriptors (serverConnectionFd).

Don't call an objc method from a signal handler. It crashes if the signal handler interrupts class_addMethod, which CoreData does all the damn time.

Fix a bug in -[PTYTask pidIsChild] that caused it to always return NO, which prevented child processes from getting waited on when not using session restoration. Issue 4612.

Add an off-by-default advanced pref to redraw the screen after Clear Buffer is selected. It's off by default because of the possible privacy implications (you might hit cmd-k quickly when your boss is walking by). Also refactor how size is used by PTYTask, VT100Screen, and PTYSession to be a VT100GridSize instead of two variables. Issue 4494.

Rename 'set directory' and 'set host and user' triggers to use the word report instead of set, because it was very confusing. Allow 'report host and user' to set only the host or only the user. Add lots of debug logging to directory stuff.

Use DEPRECATED_ATTRIBUTE to mark functions deprecated in the comments.

Fix XCode 7 warnings and failing tests. Fix a bug where lastDirectory was called on a CommandUse object because it was incorrectly typed as a CommandHistoryEntry object.

Give the user the option to append or replace log files. Remember the last used directory for the logfile save panel

Have TaskNotifier waitpid() for dead servers. I noticed waitpid() hang when the child had exited. I tried wait() to no avail. ps showed it in parens and ps -o status showed a ? in the first column, which I think means task_for_pid failed, suggesting the process is in some weird state. Oddly, after breaking out of the loop waidpid was in, the dead process disappeared on its own. See the angry comment in -killServerIfRunning for more details on why this should work without causing too much harm.

Clean up diagnostic logging about server connections at startup. Don't try to connect to orphaned servers that we know are not orphans because we're already connected to them.

Establish socket connection between client and server before fork()ing to remove sleep-retry loop after fork(). Nuke the whole sleep-retry loop.

Pass around an iTermFileDescriptorServerConnection instead of a triple of fd and two pids.

Kill the server when there’s a broken pipe.

Don’t leak unix-domain socket file descriptors. Close them when the server dies.

Move prefixing of command by iTerm2 --server into PYTTask at the last minute to ensure it's done consistently.

Session restoration improvments: Improve Sparkle support for session restoration. Don't prompt for a sparkle restart if sessions will be restored. Don't terminate jobs on shutdown for a sparkle restart. Put newlines around Session Restored message. Exponentially increase delay when first attaching, starting at 1ms. Handle failures to attach to new servers.  Fix bug where working directory was fetched from the server PID, which isn't so good when there isn't one.

Conflicts:
	sources/iTermApplicationDelegate.m

Conflicts:
	sources/iTermApplicationDelegate.m

Add a cancel button to the prompt for substitutions, thus allowing session creation anywhere to fail. Make the parameter panel less ugly.

Preserve substitutions in saved arrangements. Fixes issue 1063.

Remove a bunch of dead code.

Fix Shell>Close terminal window by implementing -[PseudoTerminal performClose:]

Truncate log files because when you do shell>log>start and you pick an existing file you're asked if you want to replace it. And it just doesn't make much sense to append anyway.

Move source into sources/ directory. Delete a few unused images in the process and fix a reference to an Aqua image in FindView