[PATCH v2 10/42] doc: Update VPN documentation for association state + agentless VPN

Add brief descriptions of the association state. Add it to parameter
descriptions as well.

Add a note about using VPN_FLAG_NO_AGENT when VPN agent is not to be
used with the VPN.
---
 doc/vpn-connection-api.txt | 4 ++--
 doc/vpn-overview.txt       | 7 ++++++-
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/doc/vpn-connection-api.txt b/doc/vpn-connection-api.txt
index 2d3e0078..df070957 100644
--- a/doc/vpn-connection-api.txt
+++ b/doc/vpn-connection-api.txt
@@ -104,8 +104,8 @@ Properties	string State [readonly]
 
 			The connection state information.
 
-			Valid states are "idle", "failure", "configuration",
-			"ready", "disconnect".
+			Valid states are "idle", "failure", "association",
+			"configuration", "ready", "disconnect".
 
 		string Type [readonly]
 
diff --git a/doc/vpn-overview.txt b/doc/vpn-overview.txt
index d2d14a0c..f5ca8013 100644
--- a/doc/vpn-overview.txt
+++ b/doc/vpn-overview.txt
@@ -66,7 +66,12 @@ VPN agent interface described in vpn-agent-api.txt is used for
 interaction between the connectivity UI and ConnMan. A VPN agent
 registered via Management interface gets requests from the VPN plugins
 to input credentials or other authentication information for the VPN
-connection and offers information about the VPN to be connected.
+connection and offers information about the VPN to be connected. When
+waiting for input via VPN agent the state of the VPN is "association"
+and after getting the input the state transitions to "connect". If the
+VPN does not wish to use VPN agent this can be explicitly defined by
+using VPN_FLAG_NO_AGENT flag in initialization indicating that the
+state is transitioned to "connect" when connecting the VPN.
 
 In addition to basic credentials, there are additional types of optional
 and control parameters. The user can dictate whether to store the
-- 
2.39.5