Added reply quoting to the GUI.

Ideally this should quote only the selected text if any text is selected
in the message viewer when the user presses reply.  At least that's how
my email client works.

I assume Go initalizes the two local varialbes I eliminated to zero,
but I thought it looked cleaner to initalize them explicitly and
and set them if inReplyTo is set.  <shrug>
Explicitly mention the topology of communication. This is already implied further below, but it is good to clear up confusion as early as possible.
[enh] added bell alert to cli on new msg
cli: print sendCommand errors instead of logging
tpm-tools is required, at least for Ubuntu
corrected spelling for the Entomb button
Merge pull request #104 from houndbee/master

Correct spelling for the Entomb button in GUI.
Merge pull request #91 from infinity0/master

Explicitly mention the topology of communication
Merge pull request #93 from leif/master

cli: print sendCommand errors instead of logging
Correctly update hasSubline flag.

Previously this would cause the GUI client to crash if a contact was
selected while a revocation notice arrived.

Fixes #96.
Don't try to read from terminal after error.

Previously an EOF from the terminal would cause one of the goroutines to
busy-loop until another recorded the error and exited the process.
Merge pull request #95 from stef/master

[enh] added bell alert to cli on new msg
Touch up reply-quoting patch for GUI.

Move indentForReply, which is now common between cli and gui, into
client.go
Merge branch 'master' of github.com:agl/pond
Merge branch 'burdges-master'
Don't clear isPending unless KX successful.

If a key-exchange failed then isPending would be cleared but the
expected elements of the contact wouldn't have been filled out. This
caused a crash during the next save() call.
Include checksums in generated shared secrets.

In order to avoid typos in shared secrets, the generated shared secrets
now have a special form that includes a checksum. Old versions of the
code will continue to work fine with them but, from this change on, the
cli and gui will reject shared secrets that have the special prefix
("r!" or "r[") but don't have a valid checksum.

The second form of shared secret (beginning "r[") is not generated yet
but causes the scrypt step to be skipped. This is laying foundations for
the future where these values can be generated.
Merge pull request #99 from glamrock/documentation

tpm-tools is required to use TPM
Clarify shared secret power after KX.

Fixes issue #100.
cli: show (at|de)tachments for outbox messages.

Also, update the error message for attaching a file that is too large so
that the unimplemented command, save-encrypted, isn't mentioned.