config UPDATE add support for TLS

New API for configuring TLS added. For the server, only it's certificate
is currently supported. For the client, only it's end-entity and
certificate-authority certificates are supported (as compared to
ietf-netconf-server module).

Each source and header files' includes were refactored (added
missing/deleted redundant).

New file to generate documentation from added to replace the old one.

New API parameters position changed. Split the API to SSH/TLS/common
files and added new common header for these.

Made changes to some internal structures and renamed some members.
diff --git a/Doxyfile.in b/Doxyfile.in
index 324e670..445709f 100644
--- a/Doxyfile.in
+++ b/Doxyfile.in
@@ -2184,7 +2184,7 @@
 # set to NO
 # The default value is: NO.
 
-HAVE_DOT               = @HAVE_DOT@
+HAVE_DOT               = YES
 
 # The DOT_NUM_THREADS specifies the number of dot invocations doxygen is allowed
 # to run in parallel. When set to 0 doxygen will base this on the number of