update gitignore
Revert "add a warning message"

This reverts commit 7ffaf17502c39ff5e16a5d412040b0b13b557fc3.
switch calloc for some c99 magic
expand requests over ipc to allow 'defering'

This will allows envoy to distinguish between full requests (like via
envoy) and partial requests (anything that just need the environmental
variables).

Otherwise envoy may not act as expected with ssh-agent and
envoy-exec/pam mixed together.
switch around ipc to allow for more complex requests

Envoy no longer automatically starts an agent upon connecting. Instead
it waits for a request to be made. This allows for a cleaner
implementation and more information to be sent along with requests.

Add the option to allow to 'defer' a start.

If a connection is marked 'deferred' envoy will not switch the status
of an agent from ENVOY_STARTED to ENVOY_RUNNING. Since envoy depends on
ENVOY_STARTED to import keys automagically, deferred starts allow us to
avoid complications between pam and envoy-exec.
remove epoll in favour of poll

There is no reason to use epoll to poll on file descriptor
change envoy_agent api
Merge branch 'ipc-defer'

* ipc-defer:
  change envoy_agent api
  remove epoll in favour of poll
  switch around ipc to allow for more complex requests
  expand requests over ipc to allow 'defering'