Unbreaks mosh on recent (> 2017/03/18) OpenBSD systems.

Signed-off-by: John Hood <cgull@glup.org>

Fixes Debian sid schroot build.

Also add build deps required for full testing:
tmux,  less (for window-resize.test)

/etc/services may not be present in a Debian sid schroot.
Also make $srcdir available to test scripts.

The failure only occurs in a Debian Sid schroot environment.

The format of debian/changelog is very rigid as it is parsed by the
build tools to determine the version number and other information.
The version number must use ~ so that 1.3.0 is considered greater than
1.3.0~rc2 for upgrades, and there must be a Debian release number like
-1 because this is not a Debian-native package.  Finally, the default
urgency is medium these days.

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

Unaligned data on ARM architectures do not perform efficiently unaligned
memory access, and in the case of ARMv7 and iOS it completely breaks. The OCB
algorithm dereferences a uint64x2_t pointer, and is replaced by a
memcpy to avoid penalties when trying to align it.

More info https://brewx.qualcomm.com/bws/content/gi/common/appseng/en/knowledgebase/docs/kb95.html

This reverts commit f002e3bb.

That commit appears to have created a race between ssh restoring
termios state and mosh-client initializing termios.

Probably fixes #844.

This seems to resolve #833.

Addresses an issue mentioned in #193.

Also makes this bit of code more readable, but the overall handling of
Unicode characters in Actions and Transitions is messy, and may get
reworked later.

Code smell pointed out by Coverity.

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