Merge branch 'hotfix/1.6.2c'
Change the http_connection to a connection.

This change is preliminary to make smews handle something else
than TCP/HTTP.

The http_connection structure is now an union inside a more generic
connection structure. This will allow the development of application
that can handle protocols over IP. The goal is absolutly not to make
smews generic, but rather provide a clean way to handle simple protocols
such ICMP.
Move generator_service in common connection struct
Move back the generator_service to http part
Move iniget member of dynamic_resource in a union
Change dynamic_resource generation in GenApps
Start some modification for GPIPH
Generates all needed info from apps for GPIP

This commit modifies the GenApps tools so that
the output handler for an above ip apps is generated
with all needed info (handlers, protocol number) and
integrated in the resources_index array.
Next step: modify smews input and output to call the handlers
Add needed code to call the doPacketIn handler
Rename icmp app to icmpv4
Fix a potential memory leak in IPv6
Change connectionsStats apps
Add messages to icmpv4
Create a connection for above ip protocol
Add connections state in mbed debug console
add_connection function
Change dopacket_in handler type (add payload size)
Changes able_to_send for gpip handler connections
Adds GPIP input management and cleans

Clean is mainly made by extracting some code
in functions (should check in funcard if it does not
overflow the stack)
Reflects packetin handler prototype changes