This is more stylistic than substantial, but it's bad enough
style to be worth fixing.

We were potentially passing (char *)NULL to string constructors.

I think this one was actually impossible to trigger.

Should resolve https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=811579

Resolves #719.

For example, do not interpret regex metacharacters within the
hostname, and avoid accidentally matching the username part of
username@hostname when they happen to match.

Signed-off-by: Anders Kaseorg <andersk@mit.edu>

Improves 679b8192 to make it simpler to
ignore mosh-client from OS X Terminal.app's "Ask before closing" process
list. (See: http://superuser.com/a/254647)

Moreover, the command displayed from ps is a completely functional one,
which was not the case in the previous approach, that mangles `argv[0]`.

Fixes #742.

Motivated by Cygwin.

Fixes #745.

There are (broken) compilers out there that accept -fstack-protector-*
parameters, but do not provide the needed ssp library. As a result,
build does not fail, but link does. Use the local check_link_flag
autoconf function to correctly test for SSP availability.

Required for the Imagination Technologies Codescape IMG MIPS
toolchain, version 2015.10 (and who knows what else).

Fixes #744.

This should resolve mobile-shell/mosh#675

Found by OpenBSD build.

* A resize action could be applied to the framebuffer but discarded
  before being applied to termios, causing them to be out of sync.

* Only every second action was skipped, instead of skipping
  consecutive resize actions, as intended.

Found by inspection, not seen in actual usage or by the window-resize
test.

This is an alternate way to resolve #417 without affecting
backward compatibility.

Add --family=auto/all.
Attempt connects to all available addresses.
Working error handling.

Fixes #629.

protobuf uses an obsolete automake pthreads detection macro,
which results in "pkgconfig --libs protobuf" returning
"-lprotobuf -pthread -lpthread" on Linux.  Remove
the unnecessary and dangerous -lpthread in that case.

Fixes #727, mosh-server crash in libutempter on Debian Sid.

This field was used during development to measure the
coverage of the ANSI terminal parser against typical
terminal input sequences.

The "handled" field has not been read by any code since
commit 1ee54cd7 (February 2011). Eliminating the field
by popular request (closes #723).