Update draft release notes after merging the first batch of topics

Documentation/RelNotes/1.8.5.txt

@@ -48,9 +48,26 @@ Updates since v1.8.4
 
 Foreign interfaces, subsystems and ports.
 
+ * remote-hg remote helper misbehaved when interacting with a local Hg
+   repository relative to the home directory, e.g. "clone hg::~/there".
+
+ * imap-send ported to OS X uses Apple's security framework instead of
+   OpenSSL one.
+
+ * Subversion 1.8.0 that was recently released breaks older subversion
+   clients coming over http/https in various ways.
+
+ * "git fast-import" treats an empty path given to "ls" as the root of
+   the tree.
+
 
 UI, Workflows & Features
 
+ * "git check-ignore -z" applied the NUL termination to both its input
+   (with --stdin) and its output, but "git check-attr -z" ignored the
+   option on the output side. Make both honor -z on the input and
+   output side the same way.
+
  * "git whatchanged" may still be used by old timers, but mention of
    it in documents meant for new users will only waste readers' time
    wonderig what the difference is between it and "git log".  Make it
@@ -61,6 +78,24 @@ UI, Workflows & Features
 
 Performance, Internal Implementation, etc.
 
+ * Many commands use --dashed-option as a operation mode selector
+   (e.g. "git tag --delete") that the user can use at most one
+   (e.g. "git tag --delete --verify" is a nonsense) and you cannot
+   negate (e.g. "git tag --no-delete" is a nonsense).  parse-options
+   API learned a new OPT_CMDMODE macro to make it easier to implement
+   such a set of options.
+
+ * OPT_BOOLEAN() in parse-options API was misdesigned to be "counting
+   up" but many subcommands expect it to behave as "on/off". Update
+   them to use OPT_BOOL() which is a proper boolean.
+
+ * "git gc" exits early without doing a double-work when it detects
+   that another instance of itself is already running.
+
+ * Under memory pressure and/or file descriptor pressure, we used to
+   close pack windows that are not used and also closed filehandle to
+   an open but unused packfiles. These are now controlled separately
+   to better cope with the load.
 
 Also contains various documentation updates and code clean-ups.
 
@@ -72,6 +107,15 @@ Unless otherwise noted, all the fixes since v1.8.4 in the maintenance
 track are contained in this release (see release notes to them for
 details).
 
+ * Setting submodule.*.path configuration variable to true (without
+   giving "= value") caused Git to segfault.
+   (merge 4b05440 jl/some-submodule-config-are-not-boolean later to maint).
+
+ * "git rebase -i" (there could be others, as the root cause is pretty
+   generic) fed a random, data dependeant string to 'echo' and
+   expects it to come out literally, corrupting its error message.
+   (merge 89b0230 mm/no-shell-escape-in-die-message later to maint).
+
  * Some people still use rather old versions of bash, which cannot
    grok some constructs like 'printf -v varname' the prompt and
    completion code started to use recently.