nvim.1: Misc. improvements (2)

Besides some minor rewording, this commit does the following:

- the argument to the `q' flag is optional, so denote it as such
- the cross references to vim (`.Xr vim 1') were pointless, just refer
  to it as `Vim'
- the `d' flag doesn't actually take any arguments; `nvim -d' works
  just fine, so make the manual reflect that
- the `L' flag is just an alias for the `r' flag, so clarify that
- there was a lot of redundancy between the `o', `O', and `p' flags,
  unify their descriptions a bit

Helped-by: Justin M. Keyes <justinkz@gmail.com>

[ci skip]

man/nvim.1

@@ -1,4 +1,4 @@
-.Dd June 26, 2015
+.Dd August 26, 2015
 .Dt NVIM 1
 .Os
 .Sh NAME
@@ -16,11 +16,10 @@
 .Fl t Ar tag
 .Nm
 .Op Ar options
-.Fl q Ar errorfile
+.Fl q Op Ar errorfile
 .Sh DESCRIPTION
 .Nm
-is a text editor based on
-.Xr vim 1 .
+is a text editor based on Vim.
 To enter commands in
 .Nm ,
 type a colon
@@ -56,7 +55,7 @@ is a function name, the file containing that function is opened
 with the cursor positioned at the start of the function.
 See
 .Ic :help tag-commands .
-.It Fl q Ar errorfile
+.It Fl q Op Ar errorfile
 QuickFix mode.
 Display the first error in
 .Ar errorfile .
@@ -75,7 +74,7 @@ Interpret all further arguments as files.
 Can be used to edit files starting with a hyphen
 .Pq Sq - .
 .It Fl -literal
-Interpret filenames literally, that is do not expand wildcards.
+Interpret filenames literally, that is, do not expand wildcards.
 Has no effect on UNIX-like systems, where the shell expands wildcards.
 .It Fl e
 Ex mode.
@@ -91,14 +90,11 @@ Only takes effect if
 .Fl e
 or
 .Fl E
-is specified before
-.Fl s .
-.It Fl d Op Ar file ...
+is specified before it.
+.It Fl d
 Diff mode.
-Show the difference between two to four files.
-If
-.Ar file
-is omitted, options related to diff mode are still set.
+Show the difference between two to four files, similar to
+.Xr sdiff 1 .
 See
 .Ic :help diff .
 .It Fl R
@@ -140,7 +136,7 @@ Sets the options 'fkmap' and 'rightleft'.
 Hebrew mode.
 Sets the options 'hkmap' and 'rightleft'.
 .It Fl V Ns Oo Ar N Oc Ns Op Ar file
-Verbose.
+Verbose mode.
 Print messages about which files are being sourced and for reading and
 writing an nviminfo file.
 .Ar N
@@ -160,18 +156,23 @@ Disable the use of swap files.
 Sets the option 'updatecount' to
 .Cm 0 .
 Can be useful for editing file(s) on a slow medium.
-.It Fl r , L
-List swap files with information about recovering them.
-.It Fl r Ar file
+.It Fl r Op Ar file
 Recovery mode.
-The swap file
+If
+.Ar file
+is omitted
+then list swap files with recovery information.
+Otherwise the swap file
 .Ar file
 is used to recover a crashed session.
-The swap file has the same filename as the text file, but with
+The swap file has the same name as the file it's associated with, but with
 .Sq .swp
 appended.
 See
 .Ic :help recovery .
+.It Fl L Op Ar file
+Alias for
+.Fl r .
 .It Fl u Ar nvimrc
 Use
 .Ar nvimrc
@@ -219,29 +220,13 @@ is less than the number of file arguments, allocate windows for the first
 .Ar N
 files and hide the rest.
 .It Fl O Ns Op Ar N
-Open
-.Ar N
-windows stacked vertically.
-If
-.Ar N
-is omitted, open one window for each file.
-If
-.Ar N
-is less than the number of file arguments, allocate windows for the first
-.Ar N
-files and hide the rest.
+Like
+.Fl o ,
+but tile windows vertically.
 .It Fl p Ns Op Ar N
-Open
-.Ar N
-tab pages.
-If
-.Ar N
-is omitted, open one tab page for each file.
-If
-.Ar N
-is less than the number of file arguments, allocate tab pages for the first
-.Ar N
-files and hide the rest.
+Like
+.Fl o ,
+but for tab pages.
 .It Cm + Ns Op Ar linenum
 For the first file, position the cursor on line
 .Ar linenum .
@@ -405,17 +390,14 @@ was started by
 .An Thiago de Arruda ,
 with a lot of help from others.
 .Pp
-Most of
-.Xr vim 1
-was written by
+Most of Vim was written by
 .An -nosplit
 .An Bram Moolenaar ,
 with a lot of help from others.
 See
 .Ic :help credits .
 .Pp
-.Xr vim 1
-is based on Stevie, worked on by
+Vim is based on Stevie, worked on by
 .An Tim Thompson ,
 .An Tony Andrews ,
 and