Added Edit > Paste Special > Paste with Literal Tabs

Also fixed "Paste Selection Escaping Special Characters" command
Updated documentation

The Toolbelt Paste History window does not correctly handle formerly paste-special'ed text

Signed-off-by: Brian Doyle <brian@balance-software.com>
Updated Paste with Literal Tabs to support large amounts of pasted data.

Previous commit only handled pasting a small amount of data, when the paste
code went into the slow paste callback cycle the don't-discard-control-codes
state was lost.  In this commit the state is passed along via the PasteContext.
Various changes per gnachman's suggestions

- removed code added to PasteContext
- moved control code stripping to pasteString:flags:
- changed tabs to spaces
- removed spaces after : in methods (e.g. arg:foo)
comment syn -> lnext
formatting
Update PTYSession.m
formatting
formatting
Retain images loaded in initialize method of PTYTextView
Unblock TaskNotifier when SIGCHLD is handled.
Merge branch 'master' of https://github.com/gnachman/iTerm2
Add some debug logging to the dvr code
Merge branch 'master' of https://github.com/bdpdx/iTerm2 into bdpdx-master
Get rid of incredibly outdated stringReplaceSubstringFrom:to: method in favor of stringByReplacingOccurrencesOfString:withString:
Clean up pasting.
Move pasting logic into iTermPasteHelper
Fix up project file for iTermPasteHelper
Add advanced setting for remembering window positions
Add preference to disable toolbar completely
Use a dedicated dispatch queue for tmux threadedReadTask:length: calls. Previously I used dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0) which actualy creates a queue every time, causing a race condition and mixed up streams.