bash-completion: add missing options and variables

- add missing short and long options
- add tests=, target_dir=, overlay_vars=

zsh-completion: add 'dump_spec' back again

bash-completion: add dump_spec=1

rebar.config.sample: fix escript_emu_args sample

Makefile: fix 'clean' and add 'distclean'

Change zsh completion script

bash-completion: add generate-appups

* fix 'clean' to remove .eunit (not .test)
* add 'distclean' to also remove deps/

Update THANKS: use my real name

Fixes

Add missing clean/2

The results returned by os:getenv() may contain unicode characters.
That said, we need to explicitly allow unicode when splitting the
environment information, otherwise badarg will be raised causing all
rebar commands to fail until the environment variable is removed.

Normally, Rebar runs eunit tests in the order the beam files are
stored in the file system (see rebar_utils:beams).  However, sometimes
it is desirable to run the tests in a different order (e.g. to
reproduce an error found on a build server).  For that case, it would
make sense to use the 'suites' parameter not just for selecting which
modules to consider, but also for choosing the order.

app_bin option was used by the install command which has been
removed in 51ed787.

- Add 'escriptize' command
- Remove variable 'dump_spec'

Rename rebar_core functions for improved readability.
Remove redundant comments and blank lines.

Fix rebar.config.sample

Restore support for so_name, port_envs and port_sources

Fix rebar_erlydtl_compiler:erlydtl_opts/1 and rebar:run/2

Fix erlydtl dependency check

Erlydtl compiler