linux-emulation: modernize a bit

- remove references to CVS, p4, etc.
- remove indirect reference to FreeBSD.org
- stop talking about old defaults
- update links

This page can be cleaned up some more, but has some valuable information
so should not be deleted without moving the information elsewhere first.

en_US.ISO8859-1/articles/linux-emulation/article.xml

@@ -261,31 +261,6 @@
 	&os;-on-&os; layers.  Others are not supposed to work properly nor
 	be usable these days.</para>
 
-      <para>&os; development happens in a central CVS repository where only
-	a selected team of so called committers can write.  This repository
-	possesses several branches; the most interesting are the HEAD branch,
-	in &os;	nomenclature called -CURRENT, and RELENG_X branches, where X
-	stands for a number indicating a major version of &os;.  As of
-	December&nbsp;2006, there are development branches for 6.X development
-	(RELENG_6) and for the 5.X development (RELENG_5).  Other branches are
-	closed and not actively maintained or only fed with security patches
-	by the Security Officer of the &os; project.</para>
-
-      <para>Historically the active development was done in the HEAD branch so
-	it was considered extremely unstable and supposed to happen to break
-	at any time.  This is not true any more as the
-	<application>Perforce</application> (commercial	version control system)
-	repository was introduced so that active development happen there.
-	There are many branches in <application>Perforce</application> where
-	development of certain parts of the system happens and these branches
-	are from time to time merged back to the main CVS repository thus
-	effectively putting the given feature to the &os; operating system.
-	The same happened with the <filename>rdivacky_linuxolator</filename>
-	branch where development of this thesis code was going on.</para>
-
-      <para>More info about the &os; operating system can be found
-	at [2].</para>
-
       <sect3 xml:id="freebsd-tech-details">
 	<title>Technical details</title>
 
@@ -444,7 +419,7 @@
 	features are added or changed while D is a minor version for bugfixes
 	only.</para>
 
-      <para>More information can be obtained from [4].</para>
+      <para>More information can be obtained from [3].</para>
 
       <sect3 xml:id="linux-tech-details">
 	<title>Technical details</title>
@@ -454,7 +429,7 @@
 	be entered in two ways: via a trap or via a syscall.  The return is
 	handled only in one way.  The further description applies to
 	&linux;&nbsp;2.6 on the &i386; architecture.  This information was
-	taken from [3].</para>
+	taken from [2].</para>
 
 	<sect4 xml:id="linux-syscalls">
 	  <title>Syscalls</title>
@@ -1468,10 +1443,8 @@ translate_traps(int signal, int trap_code)
 
 	<para>The &linux; emulation layer in &os; supports runtime setting of
 	  the emulated version.  This is done via &man.sysctl.8;, namely
-	  <literal>compat.linux.osrelease</literal>, which is set to 2.4.2 by
-	  default (as of April 2007) and with all &linux; versions up to 2.6
-	  it just determined what &man.uname.1; outputs.  It is different with
-	  2.6 emulation where setting this &man.sysctl.8; affects runtime
+	  <literal>compat.linux.osrelease</literal>.
+	  Setting this &man.sysctl.8; affects runtime
 	  behavior of the emulation layer.  When set to 2.6.x it sets the
 	  value of <literal>linux_use_linux26</literal> while setting to
 	  something else keeps it unset.  This variable (plus per-prison
@@ -2353,13 +2326,10 @@ openat(stdio, bah\, flags, mode)	/* returns error because stdio is not a directo
 	  2005.</para>
       </listitem>
       <listitem>
-	<para><uri xlink:href="http://www.FreeBSD.org">http://www.FreeBSD.org</uri></para>
+	<para><uri xlink:href="https://tldp.org">https://tldp.org</uri></para>
       </listitem>
       <listitem>
-	<para><uri xlink:href="http://tldp.org">http://tldp.org</uri></para>
-      </listitem>
-      <listitem>
-	<para><uri xlink:href="http://www.linux.org">http://www.linux.org</uri></para>
+	<para><uri xlink:href="https://www.kernel.org">https://www.kernel.org</uri></para>
      </listitem>
     </orderedlist>
   </sect1>