Use https:// for URLs in documents

Also adds contribution guidelines (for Github) with links to the wiki.

CONTRIBUTING.md

@@ -0,0 +1,2 @@
+Please refer to the [developer documentation](https://wiki.strongswan.org/projects/strongswan/wiki/DeveloperDocumentation)
+on our wiki for details regarding **code style** and [**contribution requirements**](https://wiki.strongswan.org/projects/strongswan/wiki/Contributions).

ChangeLog

@@ -1,3 +1,5 @@
 A summary of changes is available in the NEWS file. For a more
-detailed Changelog, use the repository (see HACKING) or the
+detailed Changelog, refer to the completed versions on the project's roadmap
-online interface available at http://git.strongswan.org.
+(https://wiki.strongswan.org/projects/strongswan/roadmap) or use the Git
+repository (see HACKING) or its web interface available at
+https://git.strongswan.org.

HACKING

@@ -31,7 +31,7 @@ To check out the master branch, use:
 
 or using HTTP:
 
-    git clone http://git.strongswan.org/strongswan.git
+    git clone https://git.strongswan.org/strongswan.git
 
 After a successful check out, give the autotools a try:
 
@@ -58,5 +58,5 @@ strongSwan wiki
 A wiki for users and developers, including ticket system and source browser
 is available at
 
-    http://wiki.strongswan.org
+    https://wiki.strongswan.org
 

NEWS

@@ -1081,7 +1081,7 @@ strongswan-5.0.3
   charon-tkm does not result in the compromise of cryptographic keys.
   The extracted functionality has been implemented from scratch in a minimal TCB
   (trusted computing base) in the Ada programming language. Further information
-  can be found at http://www.codelabs.ch/tkm/.
+  can be found at https://www.codelabs.ch/tkm/.
 
 strongswan-5.0.2
 ----------------
@@ -1219,7 +1219,7 @@ strongswan-5.0.0
   pluto, but currently does not support AH or bundled AH+ESP SAs. Beside
   RSA/ECDSA, PSK and XAuth, charon also supports the Hybrid authentication
   mode. Information for interoperability and migration is available at
-  http://wiki.strongswan.org/projects/strongswan/wiki/CharonPlutoIKEv1.
+  https://wiki.strongswan.org/projects/strongswan/wiki/CharonPlutoIKEv1.
 
 - Charon's bus_t has been refactored so that loggers and other listeners are
   now handled separately.  The single lock was previously cause for deadlocks
@@ -1650,7 +1650,7 @@ strongswan-4.4.0
 - The IKEv2 High Availability plugin has been integrated. It provides
   load sharing and failover capabilities in a cluster of currently two nodes,
   based on an extend ClusterIP kernel module. More information is available at
-  http://wiki.strongswan.org/projects/strongswan/wiki/HighAvailability.
+  https://wiki.strongswan.org/projects/strongswan/wiki/HighAvailability.
   The development of the High Availability functionality was sponsored by
   secunet Security Networks AG.
 
@@ -2358,7 +2358,7 @@ strongswan-4.1.7
 
 - Preview of strongSwan Manager, a web based configuration and monitoring
   application. It uses a new XML control interface to query the IKEv2 daemon
-  (see http://wiki.strongswan.org/wiki/Manager).
+  (see https://wiki.strongswan.org/wiki/Manager).
 
 - Experimental SQLite configuration backend which will provide the configuration
   interface for strongSwan Manager in future releases.

README.md

@@ -9,7 +9,7 @@ which uses the modern [**vici**](src/libcharon/plugins/vici/README.md) *Versatil
 IKE Configuration Interface*. The deprecated **ipsec** command using the legacy
 **stroke** configuration interface is described [**here**](README_LEGACY.md).
 For more detailed information consult the man pages and
-[**our wiki**](http://wiki.strongswan.org).
+[**our wiki**](https://wiki.strongswan.org).
 
 
 ## Quickstart ##

README_LEGACY.md

@@ -8,7 +8,7 @@ This document is just a short introduction of the **ipsec** command which uses
 the legacy **stroke** configuration interface. The current **swanctl** command
 using the modern [**vici**](src/libcharon/plugins/vici/README.md) *Versatile IKE
 Configuration Interface* is described [**here**](README.md). For more detailed
-information consult the man pages and [**our wiki**](http://wiki.strongswan.org).
+information consult the man pages and [**our wiki**](https://wiki.strongswan.org).
 
 
 ## Quickstart ##

TODO

@@ -4,5 +4,5 @@
 
 A roadmap of the strongSwan project is available online at:
 
-        http://wiki.strongswan.org/projects/strongswan/roadmap
+        https://wiki.strongswan.org/projects/strongswan/roadmap