Fix editstate build.

637bac76 added Destruct to disk.NewState.
Add a warning in documentation about using golang 1.0
custom tor address via env variable (closes #19)
Ignore invalid values of POND_TOR_ADDRESS.
Remove superfluous line break.
Merge branch 'kargig-fixdoc'
Merge branch 'ebfe-fix-editstate-build'
Added sendDraft and refactored to use it instead of send.

All interactions with pond.Message from cli.go and gui.go now take place in
network.go.  sendDraft func isolates updating the ratchet.

I believe this should simplify sending messages to multiple recipiants,
and reduce the chances of making mistakes when writing future UIs.

This should also fix a minor hickup in the GUI where, if the user begins
a reply, but deletes the inbox message before replying, then the reply
loses its status as a reply.
go fmt
Set the InReplyTo field when sending a draft from the GUI.
Add a note about building on Tails with < 1GB of RAM.
Fix nil-pointer defer in the case of an HTTP error from the PANDA server.
Reduce the reordering limit.

The old value (2048) was just a sanity check against storing a huge
number of keys for missing messages, but was still very large. This
seems like a more reasonable number.
Edits to the panda paper
Merge pull request #94 from arlolra/panda

Edits to the panda paper
doc: don't set ORPort.

The exit instructions were suggesting that server operators set the
ORPort, which is probably a bad idea.
Changes to support the native, OS X GUI.

This commit contains changes to the generic parts of the codebase to
support the native, OS X GUI. The GUI isn't ready yet and the bulk of it
will live in a branch for now.