[m-rev.] diff: fix and update README files

[Julien Fischer]

Fix and update README files.

README.CSharp:
README.Java:
 	The foreign_proc examples here would result in a purity error.
 	Fix them so they do not.

README.Cygwin:
 	Update urls.

README.AIX:
 	Delete the bit about the -ansi option; we no longer pass that to
 	the C compiler anyway.

README.MinGW:
README.MS-VisualC:
 	Fix grammar.

Julien.

diff --git a/README.AIX b/README.AIX
index 97f1009..ec74249 100644
--- a/README.AIX
+++ b/README.AIX
@@ -61,9 +61,6 @@ gcc 4.8.2 does work, but requires some workarounds:

      You would need the same flag when building user programs.

-  * Edit the `mgnuc' script to delete instances of `-ansi' to prevent
-    compilation problems.  Pass `--no-ansi-c' when using `mmc --make'.
-
    * gcc generates some spurious warnings about uninitialized variables.

  -----------------------------------------------------------------------------
diff --git a/README.CSharp b/README.CSharp
index e97a60e..80699b7 100644
--- a/README.CSharp
+++ b/README.CSharp
@@ -27,7 +27,7 @@ VERSIONS OF THE .NET FRAMEWORK ON MONO

  On Mono, the C# compiler has a number of aliases: gmcs, mcs, dmcs.  The alias
  with which the C# compiler is invoked controls which version of the .NET
-frameworks is used by default.  For Mono 2.8, the defaults are:
+framework is used by default.  For Mono 2.8, the defaults are:

      gmcs - .NET version 2.0
      dmcs - .NET version 4.0
@@ -126,9 +126,11 @@ foreign language interface.
  For example:

  :- pred to_string(T::in, string::out) is det.
-:- pragma foreign_proc("C#", to_string(T::in, Str::out), [],
+:- pragma foreign_proc("C#",
+    to_string(T::in, Str::out),
+    [promise_pure, will_not_call_mercury],
  "
-        Str = T.ToString();
+    Str = T.ToString();
  ").

  The implementation will include this C# code in the module's .cs file, and
diff --git a/README.Cygwin b/README.Cygwin
index d6b5cda..3b420e1 100644
--- a/README.Cygwin
+++ b/README.Cygwin
@@ -31,13 +31,13 @@ install it.  Cygwin version 1.3.1 is buggy and should not be used, but
  Cygwin 1.1.* or Cygwin 1.3.2 or later should be OK.  Recent versions of
  Cygwin can be installed directly from:

-	<http://sources.redhat.com/cygwin/setup.exe>
+	<http://cygwin.com/setup-x86.exe>

  This program will download and install the required components.

  If you want more information on Cygwin, see the site:

-	<http://sources.redhat.com/cygwin/>
+	<https://cygwin.com>

  If you're going to use a binary distribution of Mercury for Windows,
  you need to make sure that you get a version of Cygwin that is
diff --git a/README.Java b/README.Java
index 73ab394..ddf3b9d 100644
--- a/README.Java
+++ b/README.Java
@@ -73,9 +73,11 @@ foreign language interface.
  For example:

  :- pred to_string(T::in, string::out) is det.
-:- pragma foreign_proc("Java", to_string(T::in, Str::out), [],
+:- pragma foreign_proc("Java",
+    to_string(T::in, Str::out),
+    [promise_pure, will_not_call_mercury],
  "
-        Str = T.toString();
+    Str = T.toString();
  ").

  The implementation will include this Java code in the module's .java file, and
diff --git a/README.MS-VisualC b/README.MS-VisualC
index 54931ae..c27dd66 100644
--- a/README.MS-VisualC
+++ b/README.MS-VisualC
@@ -106,7 +106,7 @@ as normal.

  LIMITATIONS

-The MSVC port currently has a number of limitation:
+The MSVC port currently has a number of limitations:

  * The 'asm_fast' and 'reg' grades do not work with MSVC.
    Both use GNU extensions to C that MSVC does not provide.
@@ -200,8 +200,8 @@ directory
  * In the file lib/mercury/mdb/mdbrc

    + The backslash character, `\`, is used as an escape character in mdbrc
-    files.  You need to escape it if it occurs in any paths used in argument
-    of source commands, e.g.
+    files.  You need to escape it if it occurs in any paths used in the
+    argument of source commands, for example

          source c:\mercury-11.07\lib\mercury\mdb\mdb_doc

diff --git a/README.MinGW b/README.MinGW
index a8d4a77..62ba269 100644
--- a/README.MinGW
+++ b/README.MinGW
@@ -1,9 +1,9 @@
-This file documents the port of Mercury to Windows using the either the MinGW
+This file documents the port of Mercury to Windows using either the MinGW
  or MinGW64 ports of GCC, i.e. the i686-pc-mingw32 or x86_64-w64-mingw32
  configurations.

  NOTE: There are problems with 64-bit executables in some low-level C grades,
-namely 'asm_fast*' and 'asm_jump*' grades. The 'none*' and 'reg*' grades
+namely the 'asm_fast*' and 'asm_jump*' grades. The 'none*' and 'reg*' grades
  do appear to work correctly in our limited testing.

  -----------------------------------------------------------------------------